WASHINGTON (AP) - President Donald Trump called Friday for a "tougher and more specific" U.S.travel ban after a homemade bomb exploded on a London train.
That followed other tweets the president made on the attacks where he called the terrorists losers.
The President used his third tweet about the attack to push his so-called Muslim travel ban in the USA, saying it should be "far larger, tougher and more specific".
Trump's travel ban blocked the entry of citizens from six Muslim-majority countries for 90 days and all refugees for 120 days.
May's comments came after Trump said he would call May.
The Metropolitan Police echoed the Prime Minister's concerns, as Mr Trump's comments did not correspond with any information released by the United Kingdom authorities. The police has identified the explosion as a terrorist attack.
"We need to be smart, vigilant and tough".
16, an underground blast in Britain caused injuries to at least 22 people.
"The internet is [terrorists'] main recruitment tool which we must cut off & use better!" he tweeted.
Sadiq Khan, the Muslim mayor of London, said that his city "utterly condemns the disgusting individuals who attempt to use terror to harm us and destroy our way of life".
Mr Trump has form with London attacks.
Asked whether Trump knew something that the British public did not, PM Theresa May said: "I never think it's helpful for anybody to speculate on what is an ongoing investigation".
As a presidential candidate, Trump had proposed a blanket ban on all Muslims from entering the USA after the 2015 San Bernardino terrorist attack.
Trump's tweet seemed to envision such a "larger, tougher" ban, though he also said the measure needed to be "more specific" - which might indicate the White House is not inclined to bar people merely due to their nationality.
"We have made more progress in the last nine months against ISIS than the Obama Administration has made in 8 years", Trump wrote in another tweet.
The Supreme Court is scheduled to hear arguments on whether the travel ban is legal on October 10.
"Must be proactive & nasty!"