Donald Trump has warned that he may not have a "very good relationship" with David Cameron after the Prime Minister branded his proposal to ban Muslims from the US as "stupid".
The presidential hopeful also sniped at new London Mayor Sadiq Khan, calling him "ignorant" for comments he made after being elected and warning him: "I will remember those statements."
The presumptive Republican nominee, who is likely to go against Democrat Hillary Clinton in a bid for the White House in November, was speaking to ITV's Good Morning Britain.
On being elected as London Mayor, Mr Khan said Mr Trump was "ignorant" in his views on Islam and he risked harming security on both sides of the Atlantic.
Mr Trump said: "He doesn't know me, hasn't met me, doesn't know what I'm all about. I think they were very rude statements and frankly tell him I will remember those statements. They are very nasty statements."