Acting Homeland Security Secretary Kevin McAleenan in an interview with Hill.TV laid out the Trump administration's demands for Mexico as the country negotiates with the U.S. to avoid tariffs President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE has threatened to impose.

McAleenan said "the president was very clear, he wants to see a vast reductions in crossings through Mexico. He believes Mexico can do more to address this flow from Central America. That's the number one metric that we’re looking for."

The Trump official, who has led the Department of Homeland Security (DHS) since April, said the U.S. would like to work with Mexico to secure its own southern border, particularly a stretch along its border with Guatemala.

The acting DHS secretary noted that the U.S. would also like to see Mexico take action at natural "chokepoints" that he said criminal organizations use to transport migrants bound for the U.S. from northern triangle countries.

"We want to stop that flow there and we’re encouraging our Mexican partners to take those actions," McAleenan said, noting that the U.S. is sharing intelligence information with the Mexican government about criminal organizations that involve illegally transporting immigrants to the U.S. The DHS chief said the U.S. would like to see Mexico use that intelligence to disrupt such activities.

Additionally, he said, the U.S. is asking Mexico to impose more enforcement on its border with the U.S. "We also want to partner on our northern border. We can’t have the situation where 1,000 people in one group can cross the border at 4 a.m. without any interdiction or any effort to stop that unlawful activity," he said.

Trump announced last week he plans to impose a 5 percent escalating tariff on Mexico if the country does not do more to curb illegal immigration to the U.S.

The president also addressed the tariffs at a joint press conference early Tuesday during a state visit to the U.K. where he suggested the tariffs will likely go into effect next Monday.

"Mexico shouldn't allow millions of people to try to enter our country and they could stop it very quickly. I think they will," Trump declared, adding, “If they won't we're going to put tariffs on.”