US President Donald Trump has been blasted in a controversial Twitter rant with a CNN host calling him a man baby, embarrassing and "a piece of ****".
Reza Aslan, who hosts CNN's Believer program, slammed Trump following Sunday's attack on London Bridge and Borough Market after he appeared to link the incident to his Muslim travel ban in a series of tweets.
But Trump's tweets didn't go down well with the CNN host.
In a now deleted post Aslan tweeted: "This piece of s**t is not just an embarrassment to America and a stain on the presidency. He's an embarrassment to humankind."
He later apologised for his language and said he had lost his cool and responded in a derogatory fashion.
"I should have used better language to express my shock and frustration at the President's lack of decorum and sympathy for the victims of London," he said.
While he deleted the expletive rant, Aslan's "man baby" post remains.
The tweets caused a storm of controversy with many calling for the broadcaster to sack Aslan.
They also pointed out it's not the first time he has lost his cool over social media.
The controversy comes as the rift between London Mayor Sadiq Khan widened after the US President criticised him for the second day in a row.
While the US Embassy in London commended the strong leader, Trump has been accused of picking fights with the leader of a city hit by a terror attack.
But White House deputy press secretary Sarah Huckabee Sanders told a press briefing she didn't think the President was picking a fight with the Mayor of London at all.
Huckabee said Trump was reaffirming his commitment to national security.
"I think, again, the President's point is something he said frankly back almost two years now - a year and a half ago - when the president talked about how we have to be more committed to national security," she said.
"One of the reasons we have the travel ban here through that executive order is a focus on national security. That was the point he was trying to make."
Trump said Khan had offered a "pathetic excuse" and "had to think fast on his 'no reason to be alarmed' statement."
Trump's tweet renewed his mischaracterisation of Khan's statement to London residents following the attack that left seven people dead and dozens injured.
The mayor had told London residents not to be concerned by a stepped-up police presence in the city after the incident.
In a Sunday tweet, Trump mischaracterised Khan's remarks by suggesting the mayor had said there was "no reason to be alarmed" about the attack itself.
In a statement, Khan said: "Just like terrorists are constantly evolving and finding new ways to disrupt us, harm us, attack us, the police and experts and all of us are finding new ways to keep us safe.
"Londoners will see an increased police presence today and over the course of the next few days. No reason to be alarmed."
Khan's spokesman said he was too busy to respond to Trump's "ill-informed" tweet.
Yesterday, a spokesman for Khan responded to the latest statement from Trump, saying: "Nothing has changed since yesterday.
"The mayor is focused on dealing with Saturday's horrific and cowardly attack and working with the police, the emergency services and the Government to keep London safe."
Trump also lashed out at his own Justice Department for seeking a "watered down" version of the travel ban he signed in March instead of a broader directive that was also blocked by the courts.
The war of words is the latest episode in a long simmering conflict between Trump and Khan, a Muslim who was elected as London's mayor in May 2016.
Following his election, Khan tweeted criticism of then-candidate Trump's rhetoric, saying his "ignorant view of Islam could make both our countries less safe. It risks alienating mainstream Muslims."
Trump later challenged Khan to an IQ test during an interview on ITV.
The billionaire has been appointed by Trump to run a new external efficiency watchdog.