London Mayor Sadiq Khan has refused to reply to a critical Twitter post by Donald Trump Jr, saying he has been “doing more important things” in the wake of a deadly terrorist attack in Westminster,

“I’m not going to respond to a tweet from Donald Trump Jr, I’ve been doing more important things over the past 24 hours," Mr Khan said.

In the aftermath of Wednesday's deadly terror attack near Parliament, Mr Trump’s eldest son on Wednesday sparked controversy when he shared a link to a six-month-old story by The Independent that quoted Mr Khan saying terror attacks were "part and parcel" of living in a global city.

“You have to be kidding me?!” Mr Trump Jr said on Twitter.

In the September 2016 article, Mr Khan said major cities “have got to be prepared for these sorts of things”. He added: “It is my job to try to make sure that we are as safe as we can be.”

Many supporters of the Trump administration have shared the article since the Westminster attack, with some framing the interview as though it had only just happened.

Instead of focussing on the tweet, Mr Khan used his interview with CNN to speak about the ways in which London had responded to the attack.

"What I do know is that the threat level in London and across the country is severe, that means an attack is highly likely," Mr Khan said.

"Terrorists hate the fact that whether it’s New York, whether it’s London, whether it’s Paris, whether it’s Brussels, Istanbul, whether it’s Madrid — we have diverse communities living together peacefully getting on with each other, respecting each other.

"We’ve got a situation where Parliament is returning to normal today, City Hall is returning to normal today, tourists are returning to London today, business are returning to normal today — just the things that the terrorists hate.

"I’m not going to allow terrorists to divide London, to destroy our way of life. We haven’t in the past, not currently, not in the future."

Sadiq Khan responds to Trump Jr's tweets

In a later interview with the BBC's Today programme, Mr Khan again refused to comment on Mr Trump's son's criticism.

When pressed about the remarks he made in September, he insisted that terrorism should never be accepted.

“We must never accept terrorists being successful, we must never accept that terrorists can destroy our life or destroy the way we lead our lives,” he told host Michelle Hussain.

In pictures: Westminster attack Show all 9 1 /9 In pictures: Westminster attack In pictures: Westminster attack An air ambulance lands after gunfire sounds were heard close to the Palace of Westminster in London PA wire In pictures: Westminster attack MPs wait until the situation is under control in Westminster. 'The alleged assailant was shot by armed police,' David Lidington, leader of the House of Commons, told the house. BBC News In pictures: Westminster attack Crowds gather in Westminster after shooting incident, which police are treating as terror attack BBC News In pictures: Westminster attack Police were also called to an incident on Westminster Bridge nearby AP In pictures: Westminster attack Early reports indicate the car, which mounted the pavement on Westminster Bridge and mowed into around a dozen people, was the same vehicle which then rammed into the railings of the Palace of Westminster, just around the corner Reuters In pictures: Westminster attack Security sources described the suspected assailant as a middle-aged Asian man, who is understood to have left the car before attacking a police officer with a seven-to-eight inch knife PA wire In pictures: Westminster attack Police have asked people to avoid the immediate area to allow emergency services to deal with the ongoing incident AP In pictures: Westminster attack One woman has died and a number of others, including the police officer, have been hurt, according to a junior doctor at St Thomas' Hospital Reuters In pictures: Westminster attack At least three gun shots were heard by those inside Westminster, and proceedings in the House of Commons have been suspended AP

“We must never accept a situation where people try and divide Christians, Jews, Muslims, Hindus, and Sikhs from each other or from those who are not members of organised faith.

"We must never accept a situation where people incite hatred against people because of the faith they belong to.”