WASHINGTON (AFP) - Outrage erupted on both sides of the Atlantic on Sunday (June 5) after President Donald Trump lashed out at London Mayor Sadiq Khan in the wake of a terrorist assault in the British capital which left seven people dead.

In a series of tweets, Trump poured scorn on Khan's attempt to reassure the public after three assailants smashed a van into pedestrians on London Bridge then attacked revellers with knives.

"At least 7 dead and 48 wounded in terror attack and Mayor of London says there is 'no reason to be alarmed!'" the US president said in one message.

Khan, in an interview with the BBC shortly after the Saturday night attack, had asked Londoners and visitors to be calm and vigilant.

"You will see an increased police presence today, including armed officers and uniformed officers. There is no reason to be alarmed by this," he said.

Leading figures in the US and Britain lined up to dismiss the president's remarks, with Washington's acting ambassador to London coming out in support of Khan.

"I commend the strong leadership of the @MayorofLondon as he leads the city forward after this heinous attack," Lew Lukens said on the US embassy's Twitter account.

He also praised the "extraordinary" response from Londoners and emergency services.

Khan's spokesman issued a pointed statement saying that the mayor had "more important things to do than respond to Donald Trump's ill-informed tweet that deliberately takes out of context his remarks."

'BLOODSHED MUST END'

Trump initially said the attack showed it was time to "stop being politically correct and get down to the business of security for our people." As the scenes of panic in London were still unfolding he tweeted that it underscored the need for his contested "travel ban" on several Muslim-majority nations.

But later on Sunday he condemned the attacks in more conventional terms, sidestepping the spat with Khan and saying he had spoken with Prime Minister Theresa to extend America's "unwavering support".

"The United States will do everything in our power to assist the United Kingdom and its citizens as they work to protect their country and to bring those that are guilty to justice," he told journalists.

"This bloodshed must end. This bloodshed will end. As president, I will do what is necessary to prevent this threat from spreading to our shores."

On Sunday The New York Times said Trump had strained foreign ties with tweets which "mischaracterised" the position of London's first Muslim mayor.

"Mr. Trump either misunderstood what Mr. Khan had said or distorted it," the newspaper said, arguing that the tweets had further widened the president's rift with the US's traditional European allies.

"America is safer when we rally our friends and allies against the bad guys rather than pick fights with the good guys," the newspaper quoted Damon Wilson, President George W. Bush's top Europe adviser, as saying.

'NASTY AND UNBECOMING'

David Lammy, a Labor Party member of Parliament, tweeted of Trump's comments: "Cheap nasty & unbecoming of a national leader. Sort of thing that makes me want to quit politics on a day like this. Evil everywhere we look."

In the US, former Vice-President Al Gore told CNN that "I don't think that a major terrorist attack like this is the time to criticise a mayor who is trying to organise his city's response to this attack."

Regarding the leader's plug for his contested travel ban - which has been blocked by the courts - Cecillia Wang, deputy legal director of the American Civil Liberties Union, tweeted: "We need to be outraged when the president exploits a terrible violent crime to push his discriminatory and illegal policy."

"One of the things that concerns me about the president's tweets this morning were he in effect is calling for a Muslim travel ban again, even though the courts have continued to turn that down," Senator Mark Warner, the top Democrat on the Senate intelligence committee, said on television.

He said Trump had had ample time to tighten aviation security, adding, "Don't continue to call for this travel ban, which is, frankly... a slap in the face to Muslim Americans and others, and this in many ways may actually incite more incidents."