Trump in new Twitter attack on London mayor Sadiq Khan

Washington: US President Donald Trump launched a fresh attack Saturday on London Mayor Sadiq Khan, backing a right-wing British columnist who has been widely accused of Islamophobia and once called migrants "cockroaches."

Trump attached his latest denunciation of the mayor to a retweet by Katie Hopkins about crime in "Khan´s Londonistan" -- using a term widely perceived as a pejorative reference to the British capital´s Muslim population and Khan´s Pakistan ancestry.

"LONDON needs a new mayor ASAP. Khan is a disaster - will only get worse!" Trump wrote in response to Hopkins´ tweet, later adding the mayor was "a national disgrace who is destroying" the city.

Earlier this month the president´s plane had not even touched down in London for the start of a state visit when he tweeted that Khan was a "stone cold loser."

Khan had criticized the red carpet treatment being given Trump for the visit.

Trump said the mayor should "focus on crime in London, not me," and made a derisive reference to Khan´s height.

Khan, London´s first Muslim mayor, had led opposition to Trump´s visit, writing a newspaper article in which he compared the US leader to European dictators from the 1930s and 1940s.

At that time, the mayor´s spokesman called Trump´s tweets "childish" and "beneath the president of the United States."

On a trip to London in July last year, Trump accused Khan of doing "a very bad job on terrorism," linking immigration to a deadly wave of crime in London.

The feud began when Khan, the son of a bus driver who emigrated from Pakistan in the 1960s, criticized Trump´s travel ban on people from certain Muslim countries.

Hopkins, who wrote in support of Trump´s election campaign during her time at the Daily Mail, has been dogged by numerous allegations of Islamophobia and hate speech during her career as a columnist.

Her description of migrants as "cockroaches" in 2015 prompted a rebuke by former UN High Commissioner for Refugees Zeid Ra´ad Al Husein, who said Hopkins had used language similar to that employed by some Rwandan media outlets in the run-up to the 1994 genocide, and by the Nazis in the 1930s.