Donald Trump and Sadiq Khan have traded further blows as their public spat continued on the second day of the US president’s state visit.
Mr Trump said the Mayor of London was a “negative force” who was “not very good” at his job.
The Labour mayor accused the president of “playground behaviour” and claimed he was a “poster boy” for the far-right.
Speaking at a press conference alongside Theresa May, Mr Trump launched into an attack on Mr Khan.
“I think he has been a not very good mayor from what I understand,” he said.
“He has done a poor job, crime is up, a lot of problems, and I don’t think he should be criticising a representative of the US that can do so much good for the UK.
“He should be positive not negative – he is a negative force not a positive force.
“If you look at what he said, he hurts the people of this great country and I think he should actually focus on his job, it would be a lot better if he did that – he could straighten out some of the problems that he has caused.”
Mr Trump had begun his state visit with a Twitter broadside aimed at the mayor before Air Force One had even landed.
Mr Khan told the Press Association: “It should be a source of concern to us that Donald Trump is the poster boy for the far-right movement around the world and actually some of the things that he has done as president are deeply objectionable, far more objectionable than silly tweets he might send.”
Mr Trump branded the mayor a “stone cold loser” in a two-part tweet as he touched down in Britain on Monday.
Asked how it felt to be described in such a way, Mr Khan said: “I’m not 12 years old in a playground, I’m just surprised Donald Trump thinks he is.
“This is not about childish behaviour, this is about us as a city and many people around the country making clear our views about some of the things said and done by Donald Trump.”