Those planning on traveling between Mexico and the U.S. in the near future may want to make alternative arrangements. President Trump said that there is a “very good likelihood” that he will close the southern border next week, citing concerns around illegal immigration and drug trafficking.

“Mexico is going to have to do something, otherwise I’m closing the border,” Trump told reporters. “I’ll just close the border. And with a deficit like we have with Mexico and have had for many years, closing the border would be a profit-making operation.”

As The New York Times reports, Mexico is the America’s third-largest trading partner, with approximately $557.6 billion worth of goods traveling across the border in both directions. According to U.S. Secretary of Homeland Security Kirstjen Nielsen, closing these entry ports would undoubtedly have a huge impact on Americans.

“Make no mistake: Americans may feel effects from this emergency,” Kirstjen stated. “As personnel are reallocated to join the crisis-response effort, there may be commercial delays, higher vehicle wait times at the border, and longer pedestrian lines.”

The new Mexican government, under the leadership of president Andrés Manuel López Obrador, has been accommodating thus far. Earlier this year, it complied with a new U.S. policy that requires asylum seekers to wait in Mexico while their cases are being processed. Mexican immigration agents have also ramped up their vetting efforts at several international bridges.

“We are going to help, to collaborate,” López Obrador said in response to Trump’s latest threat. “We want to have a good relationship with the government of the United States. We are not going to argue about these issues.”

López Obrador’s willingness to cooperate came somewhat as a surprise, given that he used to be fervently anti-Trump. Prior to becoming president, López Obrador published a book titled, “Listen, Trump,” in which he criticized the White House. But he seems to have curbed his anger ever since taking office, most likely in an effort to maintain a positive relationship with the U.S.