Trump tweets for his travel ban as drama unfolds in London

US President Donald Trump took to Twitter amid the unfolding deadly drama in London on Saturday to offer help to Britain and to promote his controversial travel ban as an extra level of security for Americans.

"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 one of two tweets.

In another tweet, he advised: "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!"

At least six people were killed by militants who drove a van at high speed into pedestrians on London Bridge and then stabbed revellers in the nearby Borough Market area last night.

The three attackers have reportedly been killed by the police, while 30 victims have reportedly been rushed to hospitals.

- Reuters