Ukraine's ambassador to the US says Russia used a vacuum bomb in its invasion of the country on Monday.
According to The Telegraph, Oksana Markarova said the bomb was used in contravention of the Geneva convention.
A vacuum bomb - or thermobaric weapon - uses oxygen from the surrounding air to generate a high-temperature explosion - capable of producing a blast wave "of a significantly longer duration than that of a conventional explosive".
Markarova appealed to members of US Congress for more help as her country resists a "brutal war".
"They used the vacuum bomb today, which is actually prohibited by the Geneva convention," she said.
"The devastation that Russia is trying to inflict on Ukraine is large. They should pay, they should pay a heavy price," the ambassador said.
It comes after unconfirmed reports - and dramatic video footage - of a local government building in Kharkiv being targeted in a Russian airstrike shortly after 8am (local time).
Looks like a Russian strike right on the center of Kharkiv, in the main square right by the local government HQ this morning. pic.twitter.com/VivkeHCFr3
Earlier, Ukrainian officials confirmed at least 70 soldiers were killed in an attack on their military base on Sunday.
The attack took place at Okhtyrka, in the Sumy region which is currently under siege by Russian forces. Emergency workers were still sifting through rubble trying to find survivors, BBC is reporting.
A 64km convoy of Russian tanks and other vehicles threatened Ukraine's capital tonight, as an intense shelling attack targeted the country's second-largest city and both sides looked to resume talks in the coming days aimed at stopping the fighting.
The country's embattled president said he believed the stepped-up shelling was designed to force him into concessions.
"I believe Russia is trying to put pressure (on Ukraine) with this simple method," Ukrainian President Volodymyr Zelenskyy said today in a video address.
He did not offer details of hourslong talks that took place Monday, but he said Kyiv was not prepared to make concessions "when one side is hitting another with rocket artillery."
US satellite-imaging company Maxar Technologies said the convoy headed towards Kyiv contained hundreds of armoured vehicles, tanks, towed artillery and logistics support vehicles.
The images are from Monday.
According to an analysis of the images, the line of vehicles is now believed to lead straight from Belarus.
CNN reported every major road northwest of Kyiv ends in Belarus - the country helping Russians fund and fight Europe's first war in decades.
Satellite images taken in the last two days also show Russia is building a new bridge over River Pripyat in Belarus, just 6km from the border with Ukraine.
Belarusian President Alexander Lukashenko has been a long-standing ally of President Putin and, in the months before Russia invaded, helped stockpile weapons, soldiers and vehicles in Belarus.
Meanwhile, Ukraine's representative to the UN has said: "Do not listen to Russia's lies, listen to Ukraine's cries. We need your help."
The plea came during an emergency meeting of the UN's Security Council in which the scale of the humanitarian crisis was revealed and as claims emerge that Russia has dropped a devastating bomb on Ukrainian territory.
Sergiy Kyslytsya spoke on the last day of Russia's tenure as President of the Security Council in a meeting when member states claimed that Russia was using illegal cluster munitions.
In the sporting world, World Taekwondo has stripped Putin of his honorary taekwondo black belt. Russian teams have been suspended from all international soccer matches as well as from all international rugby "until further notice".
United States Senator Chris Murphy posted on Twitter that the Russians have fallen behind their timeline and that there have been multiple Russian equipment and logistics failures.
He made the comments after leaving a classified briefing on the Ukraine crisis.
"The ability to keep supply lines running to Ukraine remains alive, but Russia will try to encircle and cut off Kyiv in the next several weeks", Murphy said.
"The fight for Kyiv will be long and bloody and Ukrainians are rapidly preparing for street to street combat."
Just leaving classified briefing on Ukraine crisis. A few takeaways that I can share:
1/ Confirmation that the Russians have fallen behind their timeline. Ukrainian resistance has been fierce and there have been multiple Russian equipment and logistics failures.
Murphy said the United States and allies were co-ordinating to not only freeze the assets of Putin and his oligarch allies, but to seize those assets as well.
"This is likely a further step than Putin's inner circle anticipated", he said.
Ukrainian soldiers killed after attack on military base
Russian artillery has hit a military base in Okhtyrka, a city between Kharkiv and Kyiv, killing about 70 Ukrainian soldiers, the head of the region wrote on Telegram.
Dmytro Zhyvytskyy posted photographs of the damage, including a charred four-storey building.
Kharkiv, in Ukraine's northeast, has become a major battleground, Reuters reported.
Oleg Synegubov, Kharkiv's regional administration chief, said Russian artillery had pounded residential districts, even though no Ukrainian army positions or strategic infrastructure were in these locations. At least 11 people were killed, he said.
"This is happening in the daytime, when people have gone out to the pharmacy, for groceries, or for drinking water. It's a crime," he said.
Australia to fund lethal weapons for Ukraine
Australian Prime Minister Scott Morrison has announced $50 million, in US dollars, in missiles and ammunition to Ukraine.
"We're talking missiles, ammunition, we are talking about supporting them in their defence of their homeland. The overwhelming majority of that will be in the lethal category", he said.
He also announced $25 million to support international efforts with shelter, food, medical care, water and education support.
Morrison said Russia was "a pariah state".
"That's how they should be known. All around the world. No-one should have anything to do with them, frankly, right around the world."
Morrison and Defence Minister Peter Dutton have also warned Australians against flying to Ukraine to join the fight as the conflict becomes more difficult.
This is after Ukrainian President Volodymyr Zelensky called for foreign fighters to join the resistance.
Morrison said today the legal position of those who sought to travel to Ukraine to fight remained unclear.
"I'd also argue that anyone seeking to do that would find themselves on the wrong end of some very, very violent attacks", he said.
"Those disorganised civilian militias would effectively be putting people in the most extreme of situations, so we will not encourage anybody to go there and we would advise against it because largely you would be joining something, the status of which is completely unclear, and how it would be supported and how it would sit in any command structure with Ukraine's forces I think is totally unknown.
Calls to donate to relief effort
UN refugee chief Filippo Grandi issued a warning over the scale of the growing refugee crisis, commending those countries admitting refugees but saying he was concerned that the exodus was only "the beginning".
He said the UNHCR was making plans based on up to four million Ukrainians crossing borders in the coming days and weeks.
He called on world governments to donate to the relief effort, to add to nearly US$40 million in private donations made in recent days.
Reuters reports that Ukrainian ambassador to the United States, Oksana Markarova, has claimed that Russia used a vacuum bomb during the conflict.
Vacuum bombs are thermobaric weapons that create mass destruction by sucking oxygen from the air to create a high-temperature explosion.
The weapons, often referred to as the "Father Of All Bombs" are banned by the Geneva Convention and cause devastating injuries, literally sucking the air from the lungs of anyone nearby and causing a huge shockwave.
"The devastation that Russia is trying to inflict on Ukraine is large," said Markarova. "They should pay, they should pay a heavy price."
Security Council meets
In the Security Council, Russia's representative Vasily Nebenzya said that the Ukrainian people were being held hostage by "radicals" and claimed that civilians were being protected in areas now held by Russia.
He also claimed that Ukraine's decision to release prisoners to fight has led to looting.
He told Kyiv's residents that they were free to leave, saying they would be given safe passage.
He claimed that "dirty lies" were being spread by Ukraine and amplified by Western media, telling the council that Ukraine was placing forces in civilian areas and Russia was not targeting civilians.
Ukraine's representative Sergiy Kyslytsya replied that the invasion "violates the conscience of the world".
He said that Russia was attacking kindergartens, hospitals and mobile aid brigades.
"The is the action of a state determined to kill civilians," he said.
He warned that Russia was training its missiles on targets that, if struck, could lead to radioactive fallout.
That claim came as the United Nations' nuclear watchdog said missiles have hit a radioactive waste disposal site in the Ukrainian capital of Kyiv.
Kyslytsya urged the world to ignore what he said were consistent mistruths spread by Russia's representatives.
"Do not listen to Russia's lies, listen to Ukraine's cries. We need your help."
His comments to the Security Council came after Kyslytsya made an impassioned speech to the General Assembly where he told Putin that his nuclear threats were suicidal, referencing Adolf Hitler's death in 1945.
Ukrainian Ambassador in front of the UN: "If he wants to kill himself, he doesn't need to use a nuclear arsenal. He has to do what the guy in the bunker did in Berlin in May 1945"#Ukraine#Anonymous
Ukraine's President Volorymyr Zelenskyy has signed a decree temporarily lifting the requirement for entry visas for any foreigner willing to join Ukraine's International Defence Legion and fight on Ukraine's side against invading Russian troops.
The decree takes effect on Tuesday and will remain in effect as long as martial law is in place.
The brutal invasion of Ukraine rages on with blasts rocking Russia's two main targets in Kyiv and Kharkiv — cities Putin reportedly ordered the military to take by force today.
Russian forces shelled Kharkiv on Monday, rocking a residential neighbourhood, and closed in on Kyiv, in a 27km convoy of hundreds of tanks and other vehicles, as talks aimed at stopping the fighting yielded only an agreement to keep talking.
Zelenskyy said the stepped-up shelling was aimed at forcing him into concessions.
"I believe Russia is trying to put pressure [on Ukraine]," he said.
He did not offer details of the earlier talks, but said that Kyiv was not prepared to make concessions "when one side is hitting each other with rocket artillery".
Amid ever-growing international condemnation, Russia found itself increasingly isolated five days into its invasion, facing unexpectedly fierce resistance in Ukraine and economic havoc at home.
For the second day in a row, the Kremlin raised the spectre of nuclear war, announcing that its nuclear-capable intercontinental ballistic missiles, submarines and long-range bombers had all been put on high alert, following Putin's orders over the weekend.
Putin denounced the US and its allies as an "empire of lies".
Meanwhile, an embattled Ukraine moved to solidify its ties to the West by applying to join the European Union — a largely symbolic move for now, but one that is unlikely to sit well with Putin, who has long accused the US of trying to pull Ukraine out of Moscow's orbit.
Zelenskyy also announced that all prisoners who have real combat experience will be released from jail and will be able to "compensate for their guilt in the hottest spots of war".
"We have taken a decision which is not easy from the moral point of view, but which is useful from the point of view of our defences," he said.
How to take down a tank
Ukraine's defence ministry has shared an infographic with instructions on how ordinary citizens can tackle Russian tanks, highlighting the weakest points that can be targeted with Molotov cocktails.
A civilian response has formed a significant part of Ukraine's defence against Russian forces, with videos emerging claiming to show citizens in action against invading forces.
A top Putin aide and head of the Russian delegation, Vladimir Medinsky, said that the first talks held between the two sides since the invasion lasted nearly five hours and that the envoys "found certain points on which common positions could be foreseen". He said they agreed to continue the discussions in the coming days.
As the talks along the Belarusian border wrapped up, several blasts could be heard in Kyiv, and Russian troops advanced on the city of nearly three million. The vast convoy of armoured vehicles, tanks, artillery and support vehicles was 25km from the centre of the city, according to satellite imagery from Maxar Technologies.
CNN reports that Maxar Technologies estimate the length of the convoy to be almost 65km long.
People in Kyiv lined up for groceries after the end of a weekend curfew, standing beneath a building with a gaping hole blown in its side.
Messages aimed at the advancing Russian soldiers popped up on billboards, bus stops and electronic traffic signs across the capital. Some used profanity to encourage Russians to leave. Others appealed to their humanity.
"Russian soldier — Stop! Remember your family. Go home with a clean conscience," one read.
Video from Kharkiv, Ukraine's second-biggest city, with a population of about 1.5 million, showed residential areas being shelled, with apartment buildings shaken by repeated, powerful blasts. Flashes of fire and gray plumes of smoke could be seen.
Footage released by the government from Kharkiv depicted what appeared to be a home with water gushing from a pierced ceiling. What looked like an undetonated projectile was on the floor.
Authorities in Kharkiv said at least seven people had been killed and dozens injured. They warned that casualties could be far higher.
Organisers say they want to show that people around the world don't want the war and that in war "information can be more powerful than bombs".
About 40 people gathered quietly in the square, many holding anti-war placards, Ukraine and New Zealand flags, and denouncements of Putin.
Many Russians were in the crowd, standing shoulder to shoulder with Ukrainians.
"Russians don't want the war," one speaker said.
Russian-born Bvalera Terentev and Lisa Terenteva who have called Christchurch home for the past six years are appalled at the war.
"We want to show our support not only for Ukraine but for the world against this lunatic Putin and his team who collectively are aggressive against Ukraine, the western way of understanding, democracy, freedom, intellectual development and progress," Bvalera said.
The United Nations' nuclear watchdog says missiles have hit a radioactive waste disposal site in Kyiv, but there are no reports of damage to the buildings or indications of a release of radioactive material.
International Atomic Energy Agency director General Rafael Grossi said on Sunday Ukrainian authorities informed his office about the overnight strike. He says his agency expects to soon receive the results of radioactivity monitoring.
The report came a day after an electrical transformer at a similar disposal facility in the Ukrainian city of Kharkiv was damaged.
Such facilities typically hold low-level radioactive materials such as waste from hospitals and industry, but Grossi says the two strikes highlight a "very real risk". He says if the sites are damaged there could be "potentially severe consequences for human health and the environment".
US expels 'spies', ICC opens probe into war crimes
The Biden administration's action came as pressure was heaped on Russia by the announcement of a probe into alleged war crimes committed by Russia during its invasion of Ukraine.
The chief prosecutor of the International Criminal Court said he plans to open an investigation "as rapidly as possible" into possible war crimes and crimes against humanity in Ukraine.
Prosecutor Karim Khan said the investigation will look at alleged crimes committed before the Russian invasion, but added that "given the expansion of the conflict in recent days, it is my intention that this investigation will also encompass any new alleged crimes falling within the jurisdiction of my office that are committed by any party to the conflict on any part of the territory of Ukraine".
The island, a key territorial point in the Black Sea, was "completely destroyed", the Navy said.
A widely shared video purportedly included audio of the defenders' defiant resistance when a Russian warship demanded they surrender.
"This is a Russian warship. I propose you lay down arms and surrender to avoid bloodshed and unnecessary victims. Otherwise, you'll be bombed," the Russians said in the clip.
The Ukrainian defenders responded repeatedly, "Russian warship, go f*** yourself."
Communications with the border guards and armed forces on the island were severed after an aerial attack and artillery shelling.