Trump speaks with Theresa May on brutal London terror attacks

Trump also offered the US' "full support" in investigating the two terror attacks at the iconic London Bridge and Borough Market in the heart of the UK's capital.

"He praised the heroic response of police and other first responders and offered the full support of the United States Government in investigating and bringing those responsible for these heinous acts to justice," the White House said in a statement after the phone call between the two leaders.

At least six people were killed and 30 others injured today in two terror attacks at central London landmarks in which police shot dead three suspects.

Today's attacks came just days ahead of the UK general election to be held on June 8.

"Whatever the United States can do to help out in London and the UK, we will be there - we are with you. God bless!" Trump said in a tweet. He described the incidents as "brutal" terror attacks.

May said the "terrible incident" in London was being treated as a "potential act of terrorism".

Labour leader Jeremy Corbyn said his thoughts were with victims after the "brutal and shocking incidents" in London.

London mayor Sadiq Khan condemned it as "deliberate and cowardly attack".

Today's were the third terror attack to strike the UK this year, after a man drove a car into pedestrians on Westminster Bridge in March and the bomb attack on an Ariana Grande concert in Manchester two weeks ago.

On 22 May, 22 people were killed and 116 injured in a suicide bombing at Manchester Arena.

The attacker, identified as 22-year-old Salman Abedi, detonated a home-made bomb in the arena's foyer as crowds were leaving a performance by US singer Ariana Grande late in the evening.

On 22 March, six people died, including the attacker, and at least 50 people were injured in an attack near the Houses of Parliament.

Attacker Khalid Masood drove his car at pedestrians on the pavement on Westminster Bridge before crashing into a perimeter fence. Armed with a knife, Masood then left the vehicle and ran towards Parliament, where he was shot dead by police.