Donald Trump isn't just stirring up debate at home. As the presumptive Republican nominee, he has some trans-Atlantic controversy too.

FOX's Simon Owen reports from London:

British Prime Minister David Cameron called Donald Trump's proposal to ban Muslims from entering the U.S. divisive and stupid.

Trump responded, appearing on one of the morning shows here, Good Morning Britain:

(Trump) "Looks like we're not going to have a very good relationship, who knows? I hope to have a good relationship with him."

The Prime Minister's office saying Cameron stands by his remarks.

Trump also responding to the Mayor of London Sadiq Khan, himself a Muslim, after he said Trump is ignorant about Islam:

(Trump) "I think they are very rude statements. And frankly, tell him I will remember those statements. They are very nasty statements."

Trump challenging the Mayor to an IQ test.

In London, Simon Owen, FOX News.

Follow Simon Owen on Twitter: @bigso