Donald Trump claimed “we haven’t been tough enough” when dealing with terrorism, after suggesting the accused attacker was in the sight of Scotland Yard during an earlier tweet.
The police have identified a man they believe to be behind the explosion on Friday morning.
At least 22 people have been injured in the blast, from an improvised bucked bomb, which was triggered with a timer on the District Line train at 8.20am, according to police.
Responding to the incident, the US President said: “It’s a terrible thing, it keeps going and going.
“We have to be very smart, we have to be very, very tough – which perhaps, we are not nearly tough enough.
“But, that is an absolutely terrible thing.”
Mr Trump revealed he had been briefed on the events and would phone Prime Minister Theresa May to discuss it.
Prior to his statement on the lawns outside the White House, Mr Trump wrote on Twitter: “Another attack in London by a loser terrorist.
“These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!
“Loser terrorists must be dealt with in a much tougher manner. The internet is their main recruitment tool which we must just off and use better.”
Prime Minister Theresa May condemned the “cowardly attack”, saying it involved a device “clearly intended to cause significant harm”.
She said the terror level in the UK would remain at severe – meaning an attack is highly likely – but would be kept under review.
The Met Police’s Assistant Commissioner Mark Rowley, the country’s most senior counter-terrorism officer, said “many urgent inquiries” are ongoing.
He said: “We now assess this was a detonation of an improvised explosive device.”
Asked if it was clear whether the person responsible was on the train at the time, Mr Rowley added: “It’s very much a live investigation and we are following down the lines of inquiry as I said.”
‘We need to be tougher’ Donald Trump responds to Parsons Green terror attack have 333 words, post on www.express.co.uk at 2017-09-15 17:51:13. This is cached page on Europe Breaking News. If you want remove this page, please contact us.