WASHINGTON (Reuters) – U.S. President Donald Trump said on Monday the agreement allowing the United Kingdom to leave the European Union may make trade between Washington and London more difficult.

He also told reporters outside the White House that the deal sounded like it would be good for the European Union, but he expressed concern about where the deal left trade between the UK and the United States.

“I think we have to take a look seriously whether or not the UK is allowed to trade. Because right now if you look at the deal, they may not be able to trade with us,” he said. “And that wouldn’t be a good thing. I don’t think they meant that.”

He said he hoped British Prime Minister Theresa May would be able to address the problem, but he did not specify which provision of the deal he was concerned about.

Under the deal secured with EU leaders on Sunday, the UK will leave the bloc in March with continued close trade ties. But the odds look stacked against May getting it approved by a divided British parliament.