NEW YORK - Presumptive Republican presidential nominee Donald Trump has backtracked on his proposal to ban Muslims from entering the United States, saying it was “only a suggestion”.

Responding to strong criticism from the newly elected Mayor of London, Sadiq Khan, Trump said in an interview with Fox News Radio, the planned ban was only “temporary.”

Trump said the United States has “a serious problem (of Islamic terrorism). It’s a temporary ban. It hasn’t been called for yet. Nobody’s done it. This is just a suggestion until we find out what’s going on.”

Trump’s proposal last year of “a total and complete” ban on foreign Muslims entering the US “until our country’s representatives can figure out what the hell is going on” has become a signature tenet of his campaign.

Though the proposal has been criticised as racist and potentially unconstitutional, the candidate has stood by it throughout the Republican primary. His apparently tempered stance could be seen as a result of his pivot from the more hardline Republican base to the national public as he eyes the general election.

Earlier this week, when asked how his policy would affect London’s first Muslim mayor Sadiq Khan, Trump told The New York Times that “there will always be exceptions.”

Khan subsequently rejected the overture, blasting the candidate’s “ignorant” view of Islam.

“This isn’t just about me — it’s about my friends, my family and everyone who comes from a background similar to mine, anywhere in the world,” Khan said.

“Donald Trump’s ignorant view of Islam could make both our countries less safe — it risks alienating mainstream Muslims around the world and plays into the hands of the extremists,” Khan said in a statement.

Khan, the London-born son of Pakistani immigrants, was elected last week by a wide margin after a campaign that saw his Conservative rival Zac Goldsmith accuse him of having shared platforms with Islamic extremists.

The mayor said Tuesday that Trump and people who agree with him “think that western liberal values are incompatible with mainstream Islam — London has proved him wrong.”

Trump said he was “happy to see” Khan’s election and hoped “he does a good job.”

Meanwhile, Trump brushed off his Capitol Hill critics Wednesday, declaring he doesn’t need House Speaker Paul Ryan or other leery Republican leaders, even as he prepared to sit down with them. His defiant message came amid new signs that he might be right, with Republican voters becoming more willing to embrace him.

“If we make a deal, that will be great,” Trump told Fox News Channel when asked about Thursday’s meeting with Ryan, who has so far refused to endorse him. “And if we don’t, we will trudge forward like I’ve been doing and winning all the time.”