LONDON—U.S. Presidential hopeful Donald Trump said Britain would be “better off without” the European Union, weighing in to a heated debate in Britain ahead of a national referendum next month on the U.K.’s continued membership.

“I would say that they are better off without it, personally, but I’m not making that as a recommendation, just my feeling,” he said in an interview on Fox News Thursday when asked about his views on Britain’s withdrawal from the bloc, known as Brexit.

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