Donald Trump has waded into the Brexit debate by stating that Britain would be "better off without" the European Union.

The Republican presidential candidate, said "migration has been a horrible thing for Europe" and that Britain should leave.

His statement came as David Cameron vowed to oppose Mr Trump's Muslim ban if the billionaire becomes president.

"I think the migration has been a horrible thing for Europe. A lot of that was pushed by the EU," Mr Trump said.

"I would say they are better off without it, personally, but I'm not making that as a recommendation, just my feeling.

"I know Great Britain very well, I know the country very well, I have a lot of investments there.

"I would say that they are better off without it, but I want them to make their own decision."

Mr Trump's comments came two weeks after President Barack Obama, writing in The Daily Telegraph, urged Britain to stay in the EU when it votes on June 23.

Earlier this week, Mr Trump criticised Barack Obama for supporting Mr Cameron in his campaign for Britain to remain in the EU.

"I didn't think it was a good thing for him to do it," he said.