Donald Trump has warned that he may not have a good relationship with British Prime Minister David Cameron after the Conservative branded his proposal to ban Muslims from entering the United States as "divisive, stupid and wrong". The US presidential hopeful also warned that he "will remember" similar statements made by Labour's Sadiq Khan, attacking the new London Mayor as "very rude".

The presumptive Republican nominee, who looks likely to go against Hillary Clinton in the November US presidential election, was speaking to Piers Morgan on ITV's Good Morning Britain on Monday (16 May 2016). His comments come shortly after Cameron refused to apologise for his attack on Trump.

Trump initially said he "didn't care" about Cameron's statement but admitted the normally close relationship between UK prime minister and US president could falter should he be elected.

"It looks like we're not going to have a very good relationship," he said. "I hope to have a good relationship with him, but it sounds like he's not willing to address the problem either."

Pressed further on the terms "stupid" and "divisive" used by Cameron, Trump added: "Number one, I'm not stupid. I can tell you that right now. Just the opposite.

"Number two, in terms of 'divisive', I don't think I'm a divisive person. I'm a unifier – unlike our president now."

Trump also issued a strong attack on Khan, who had berated Trump as "ignorant" just days after winning the London Mayoral election. Trump had originally suggested Khan would be an "exception" to his ban on Muslims entering the US should he wish to visit.

"When he won I wished him well," Trump said. "Now, I don't care about him."

When asked if he was offended by Khan's statements, Trump added: "Yeah, I am. He doesn't know me, never met me, doesn't know what I'm all about.

"I think they're very rude statements. Tell him I will remember those statements. They're very nasty statements."

In December 2015, Trump sparked condemnation from world leaders when he called for a "total and complete shutdown of Muslims entering the United States". The billionaire tycoon said Muslims should be barred from entering the US until the nation's leaders could "figure our what is going on".

Cameron said the comments were "stupid, divisive and wrong", while Khan claimed Trump's "ignorant view of Islam" could make the UK and the US less safe. He added: "It risks alienating mainstream Muslims around the world and plays into the hands of the extremists."