Mexico and the U.S. will continue talks Friday about efforts to curb the flow of Central American migrants to the southern U.S. border, Mexican Foreign Secretary Marcelo Ebrard said in a short statement late Thursday.

Mexico is trying to reach an agreement with the U.S. on migration in order to avoid a series of escalating tariffs President Donald Trump has threatened to impose on all Mexican imports. The first round of tariffs would begin Monday with a 5 percent duty on imports ranging from fruits to machinery.

Ebrard said talks are advancing, but provided no details other than mentioning that Mexico discussed making greater use of its National Guard in the southeastern portion of the country.

Vice President Mike Pence, who spent Thursday in Pennsylvania, told reporters that talks were progressing but that there was no agreement.

“The president announced 5 percent tariffs on all goods from Mexico. That is the policy of the United States,” Pence said. “The president has said what he means and meant what he said. We made that very clear to the Mexican delegation yesterday. For anything to change before or after Monday, Mexico has to step up. Mexico has to take decisive action to end this surge of illegal immigration that is literally overwhelming our southern border.”

The president announced on May 30 that he would levy a 5 percent tariff on imports from Mexico on June 10 and raise them 5 percentage points on the first of each month to a high of 25 percent on Oct. 1 unless Mexico does more to stem the flow of migrants from Central America to the southern U.S. border.

Amid reports Thursday that the two sides were making progress and that the administration was reconsidering the levy, a White House official sought to dampen any optimism. “Has the president given any indication he doesn’t want these tariffs to go into place?” the official said.

Press secretary Sarah Huckabee Sanders issued a statement later, saying the “Position has not changed, and we are still moving forward with tariffs at this time.”

Trump’s use of across-the-board tariffs has stirred objections on Capitol Hill.

On Thursday, House Ways and Means Chairman Richard E. Neal, D-Massachusetts, said if Trump imposes the duties on Monday that he would introduce a resolution of disapproval to repeal them.

“The President’s proposed tariffs would hurt American workers, businesses, and consumers,” he said. “Commandeering U.S. trade policy to influence border security is an abuse of power. If the President does declare a national emergency and attempt to put these tariffs into place, I will introduce a resolution of disapproval to stop his overreach.”

If the Democratic-controlled House approved the resolution, the Republican-controlled Senate could be put on the spot. Senate GOP members, despite grumbling and increasingly sharp criticism of Trump’s use of tariffs, have declined to take legislative action to block or repeal duties on steel and aluminum or on $250 billon of Chinese imports. Several talked about taking potential action earlier this week, but the view seemed generally to be one of reluctance.

Any legislative action would require veto-proof margins of support in each chamber since Trump seems likely to veto any congressional attempt to limit his authority. Two-thirds of the House and the Senate would have to vote to override the president’s rejection. 

The talks come as Customs and Border Protection reported that agents detained or turned back more than 144,000 migrants at the southwest border in May, up 32 percent from April. The number includes individuals who turned themselves in at or between ports of entry to seek asylum, as well as those who tried to slip by without being detected. May is the third consecutive month in which the total has surpassed 100,000.