Donald Trump has said the White House should not be criticised for quoting a Fox News analyst who accused British intelligence of helping former president Barack Obama spy on him.

There is no evidence such spying took place and GCHQ, the British electronic intelligence agency, has called the allegation "utterly ridiculous".

During a joint press conference with German Chancellor Angela Merkel, the US president said that "we said nothing. All we did was quote a certain very talented legal mind who was the one responsible for saying that on television".

He added: "You shouldn't be talking to me, you should be talking to Fox."

He also stood firm on his unproven wiretapping allegation with a reference to 2013 reports that the US listened in on Mrs Merkel's phone calls.

Mr Trump said that when it comes to wiretapping, "at least we have something in common, perhaps".