U.S. President Donald Trump on Tuesday warned fellow Republicans in Congress not to block his efforts to impose tariffs on Mexico as part of his broader immigration fight amid reports that lawmakers are considering steps to block his latest trade salvo.

Trump, speaking at a news conference in London during a state visit to the United Kingdom, said he doubted congressional Republicans would follow through with any rebuke, and that he expected tariffs on goods imported from Mexico to go forward next week.

"I don't think they will do that. I think if they do, it's foolish," he said, citing his broad support generally among members of the party.