LONDON/WASHINGTON (Reuters) - 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.

Frustrated over the migrant crisis at the southern U.S. border with Mexico, Trump last week said he would impose tariffs on Mexican imports starting June 10 unless Mexico halted the flows of Central American immigrants crossing Mexico to reach the United States.

Mexican officials, eager to avoid punitive tariffs and salvage a separate trade agreement between the two countries and Canada, have embarked on a diplomatic push in Washington to reach an agreement over the migrant flows.

Trump on Tuesday acknowledged the U.S.-Mexican talks this week but said the tariffs were still likely.

On Monday, the Washington Post reported that congressional Republicans were discussing whether they may need to act to block Trump’s planned tariffs, which has been criticized by the U.S. Chamber of Commerce and industry groups who worry about increased costs for U.S. businesses and consumers.

Republicans and Democrats are also worried about the economic impact of Trump’s latest tariff threat, particularly for the U.S. agriculture and auto sectors. Tariffs could also derail a separate trade deal to replace the North American Free Trade Agreement (NAFTA) that the Trump administration is trying to get Congress to approve.

Politico on Monday also reported Republicans were weighing whether a vote to block the tariffs was possible or whether Democrats, who control the U.S. House of Representatives, might act first.

Republicans were more cautious in public comments on Tuesday even as some acknowledged congressional action regarding the Mexican tariffs, if they materialize, is likely.

Rob Portman, a member of the Senate Foreign Relations and Homeland Security panels, said lawmakers would be forced to act because Trump was imposing the tariffs using his emergency powers, “which is going to require another vote of disapproval.”

“If the tariffs do go into effect on Monday ... Congress is likely to have a vote,” he told CNBC.

U.S. House Republican leader Kevin McCarthy said he thinks a solution will be worked out to avoid the tariffs.

“I hope we can get to a good place, but I think the president has to use every device at his disposal,” Republican Senator Thom Tillis told Fox News.

House Majority Leader Steny Hoyer, the chamber’s No. 2 Democrat, told Reuters he would discuss the tariffs with Democratic committee chairs on Wednesday. “They ought to be focused on that and the consequences it has on our economy and American consumers,” Hoyer said, adding that he hoped Republicans were interested in tackling the tariffs as well.