Donald Trump has been criticised for tweeting out unconfirmed information about the London Bridge terrorist attack and using the incident to argue in favour of his so-called Muslim travel ban.

The President re-tweeted a headline about the deadly incident at London Bridge and Borough Market from the Drudge Report, a right-wing outlet.

“Fears of new terror attack after van ‘mows down 20 people’ on London Bridge…” the headline read, which he re-tweeted on his personal Twitter account.

NBC responded with its own tweet, warning its audience not to rely on the President’s social media.

“Pres[ident] Trump has used Twitter to share news report on London incident. We aren’t relaying president’s retweet, as the info is unconfirmed.”

Within 20 minutes, Press Secretary Sean Spicer tweeted: “National Security team has briefed @POTUS on situation at #LondonBridge and will continue to provide updates.”

The President then sent a second message, about 40 minutes later.

“We need to be smart, vigilant and tough. We need the courts to give us back our rights.

"We need the Travel Ban as an extra level of safety!” he said, referring to his controversial executive order that blocked immigrants from six Muslim-majority countries until it was knocked down by federal courts.

On Saturday evening just after 10pm several men in a white van ploughed into pedestrians on London Bridge before exiting the vehicle and stabbing multiple people near a popular pub beside Borough Market. Three suspects were shot dead by the police.

Mr Trump's apparent attempt to score political points relating to his controversial executive order in the wake of the attack prompted outrage from a succession of experts and human rights lawyers.

John Horgan, a terrorism and political violence expert at Georgia State University, called the President an “Opportunist-in-Chief”, while Adam Wagner, a human rights barrister, said: “Message from London: political point scoring is the absolute, LAST thing we need right now.”

Mr Trump’s third tweet on the attack was more in line with previous messages sent to the UK after the Manchester Arena explosion, which killed 22 people, and the Westminster stabbing in March.

“Whatever the United States can do to help out in London and the UK,” he wrote, "we will be there – WE ARE WITH YOU. GOD BLESS!”

London Bridge Terror Attack Show all 16 1 /16 London Bridge Terror Attack London Bridge Terror Attack Armed police on Borough High Street as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack Armed Police talk to members of the public outside London Bridge Hospital as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack Police Officers outside the Barrowboy and Banker Public House on Borough High Street as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack Armed Police talk to members of the public outside London Bridge Hospital as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack Armed police on Borough High Street as police deal with a 'major incident' at London Bridge PA London Bridge Terror Attack Emergency services near the scene of the incident Screengrab London Bridge Terror Attack People run down Borough High Street as police are dealing with a "major incident" at London Bridge Reuters London Bridge Terror Attack Emergency services arrive at the scene near Borough market at London Bridge Carl Court/Getty Images London Bridge Terror Attack Emergency personnel on London Bridge as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack Police sniffer dogs on London Bridge as police are dealing with a "major incident" at London Bridge PA London Bridge Terror Attack A second helicopter lands on London Bridge as police are responding to three incidents in the capital, amid reports that a vehicle collided with pedestrians on London Bridge, Scotland Yard said. Officers are dealing with reports of stabbings in Borough Market, where armed officers attended and shots were fired. They are also at an incident in the Vauxhall area PA London Bridge Terror Attack Police attend to an incident on London Bridge in London REUTERS London Bridge Terror Attack Police attend to an incident on London Bridge in London, Britain Reuters London Bridge Terror Attack A police officer escorts members of the public to safety at London Bridge Getty Images London Bridge Terror Attack Police attend to an incident on London Bridge in London, Britain Reuters London Bridge Terror Attack Police attend to an incident near London Bridge in London, Britain Reuters

Vice President Mike Pence echoed this message, tweeting: “Our thoughts & prayers are w/ the victims, courageous first responders & all the people of London. As President Trump said: WE ARE WITH YOU.”

Mr Trump’s second and third tweets were shared on his official White House twitter page. His first was not.

Other senior politicians followed suit.

'I was throwing bottles, glasses, stools, chairs, but I was defenceless' says London Bridge eyewitness

Republican House Speaker Paul Ryan said: “We stand resolute with our friends in London and send prayers to the victims. Terror and hate will never triumph.”

Chuck Schumer, the Senate’s Democratic minority leader, said: “My heart is with the people of London, the victims of this string of terrorist attacks, and their families. You are all in our prayers.”

The US State Department issued a statement, condemning the “cowardly attacks”.

“We understand UK police are currently treating these as terrorist incidents. The United States stands ready to provide any assistance authorities in the United Kingdom may request,” it read.