London attack: Donald Trump calls Theresa May pledging to work more closely with UK

Reports say the Prime Minister raised the matter of the President's earlier 'unhelpful' speculation that the perpetrators were known to the authorities

Prior to the phone call, the Prime Minister publicly admonished Mr Trump for his speculative tweets (AP)

Donald Trump has spoken with Theresa May to pledge closer collaboration with Britain over terrorism after the Parsons Green attack.

Unnamed sources claimed the Prime Minister raised the matter of Mr Trump's speculation about who was responsible for the West London explosion.

The President's assertion that the London attackers "were in the sights of Scotland Yard" appeared to irk Ms May, being either the revelation of shared intelligence or what she called "unhelpful speculation".

Following a meeting of the Government's Cobra emergency committee, Ms May said: “I never think it's helpful for anybody to speculate on what is an ongoing investigation.''

The US President used the day of the terror attack in Parsons Green to call for a "far larger, tougher" travel ban in the US.

In his usual bombastic style, he fired off a tweet, saying: "Another attack in London by a loser terrorist! These are sick and demented people who were in the sites of Scotland Yard. Must be proactive."

Scotland Yard echoed the concerns of Ms May by saying the President's comments did not correspond with any information released by the UK authorities.

Downing Street said that during the phone call, Mr Trump had offered his condolences for this morning's attack which has left at least 29 people injured.

A spokesman said: "President Trump called the Prime Minister earlier today to offer his condolences over this morning's cowardly attack in London.

"They also discussed North Korea's latest missile test, agreeing it was a reckless provocation and that China must now use all its leverage to bring pressure to bear on the North Korean regime to ensure they change course and end these illegal tests."

During a press conference at the Rose Garden, Mr Trump confirmed that he had been briefed on London but did not say whether this happened before or after he sent out his tweets.

Following the Manchester attack, intelligence from the UK investigation, including the name of the attacker and photographs of his explosive devise, was leaked to the US media by American government sources, causing a diplomatic row. Intelligence sharing was briefly suspended between the close allies, but quickly resumed following a visit to the UK by US Secretary of State Rex Tillerson.