LONDON — President Trump said he would take a “tougher” attitude toward Brexit negotiations than the approach now being used by Prime Minister Theresa May of Britain.

“Would it be the way I negotiate? No, I wouldn’t negotiate it the way it’s negotiated ... I would have had a different attitude,” he said in an interview with ITV, a British television network, that was broadcast Sunday night.

“I would have said that the European Union is not cracked up to what it’s supposed to be,” he said.

Britain is preparing to leave the European Union in March 2019. The complex negotiations have moved slowly and Mrs. May’s cabinet seems deeply divided over how best to separate Britain from the 28-nation bloc.

Mr. Trump expressed annoyance with European Union trade policy. “We cannot get our product in,” he said. “It’s very, very tough. And yet, they send their product to us — no taxes, very little taxes.”