South Korea claims Kim Jong-un sent a drone to spy on their missile defenses. Photo/AP
South Korea has threatened military action against the North after confirming Kim Jong-un sent a drone to spy on their new missile defenses.
Seoul strongly condemned the spying mission, calling it an "act of provocation" and said if Kim Jong-un does not stop "our military will forcefully retaliate".
Meanwhile two US officials told CNN that increased activity has been detected at the dictator's nuclear testing site, possibly indicating preparations for a sixth test, , according to Daily Mail.
While the officials said the much-anticipated test is far from certain, there are concerns it could be timed to coincide with a visit by Chinese officials to Washington DC on Wednesday.
Satellite images published this month by observation group 38North confirmed continuing activity at the Punggye-ri site, though its analysts said the site still appears to be in standby mode.
If a test were carried out, it could prompt pre-emptive strikes by the "armada" President Trump has stationed in the region, and provoke all-out war in the region.
In a sign that the situation could rapidly deteriorate, Trump tweeted on Tuesday that efforts by Chinese leader Xi Jinping to control North Korea had "not worked out".
The President has repeatedly said that if the Chinese could not 'solve' the North Korea issue, "we will."
South Korea's military said on Wednesday that a drone found earlier this month on a mountain near the Demilitarised Zone was confirmed to have been from North Korea A spokesman said it was a "grave provocation" that violated the Korean War truce.
The drone crashed while returning to the North and was found equipped with a camera and aerial photographs of the U.S. THAAD anti-missile defense system site in a southern region of South Korea, South Korean officials said.
The origin and flight path of the drone were confirmed in an analysis of the onboard computer and camera, officials said.
"The intrusion of our airspace by the North Korean drone and photographing of a military base is a violation of the Armistice and an agreement on non-aggression and is an act of grave provocation," Joint Chiefs of Staff official Jeon Dong-jin said.
"We strongly condemn the North's continued attempts at penetrating the South with drones and once again, demand all acts of provocation are halted," he added.
The drone had been launched in the Kumgang-gun area in Kangwon Province on May 2, the defense ministry's spokesman Moon Sang-gyun told the briefing.
"The aircraft proceeded to fly for a total of five hours and thirty minutes and its assessed flight path matched the evidence seen in the photographs taken by it," said Moon.
Moon added the drone had been found with roughly 550 photographs and the military assessed it aimed to collect information on South Korean military bases and the anti-missile THAAD system located in Seongju.
The drone had turned around in Seongju after taking photographs, Moon said, and later crashed in Inje-gun in the South's Gangwon Province where it was found by South Korean military on June 9.
The U.S. THAAD anti-defense system has been deployed in South Korea to counter a growing missile threat from North Korea. North Korean drones are known to have flown over South Korea several times.
The defense ministry said on Wednesday this latest drone largely matched another North Korean drone discovered in 2014 on Baengnyeong Island, near the inter-Korean maritime border.
Japan also sought to reassure its citizens over fears of an attack by North Korea by carrying out a public test of its own missile defenses on Wednesday.
A PAC-3 Patriot battery drove on to the Asaka Self Defense Forces base near Tokyo, deployed its radar antenna and raised its missile launcher to firing position. The drill is one of four being held across Japan.
"Making this public is a way to reassure people about their safety and bring peace of mind," Akinori Hanada, an Air Self Defense Force major, told reporters.
Increased tensions on the Korean Peninsula came after Otto Warmbier, a University of Virginia student imprisoned by Kim Jong-un's regime for trying to steal a propaganda poster, died after being handed back to the US in a coma.
While it is unclear how Warmbier ended up with the severe brain damage which ultimately caused his death, several prominent US politicians - including Senator John McCain - have accused North Korea of state-sponsored murder.