London terror attack: Mayor's praise for bravery under fire

London Mayor Sadiq Khan has addressed residents in the wake of a terror attack, to reassure residents and praise the first responders for their efforts. 

In a message spread through social media, Mr Khan says his thoughts are with the families of those who lost loved ones, including the family of the Metropolitan Police officer Keith Palmer who was stabbed by the armed assailant. 

"I want to show my gratitude, on behalf of all Londoners, to the police and emergency services who have shown tremendous bravery in exceptionally difficult circumstances," Mr Khan says. 

Mr Khan says additional police, both armed an unarmed, will be patrolling the city overnight to provide reassurance. 

But a Trump family member is less than sold on Mr Khan's stance on terrorism. 

Donald Trump Jr, the son of the US President Donald Trump, took to Twitter following news of the attack to express some confusion. 

"You've got to be kidding me?" he tweeted, with a link to an article about Mr Khan in September. 

The Independent story quoted the Muslim mayor, who said terror attacks were "part of living in a big city".

Mr Khan also said part of accepting attacks on the city meant the city could be vigilant, including equipping the police force with resources to handle a terrorist act.