Mexican Foreign Minister Marcelo Ebrard said Monday that his country would reject a proposed solution to the immigration and tariff stand-off with the U.S. that would involve it keeping Central American asylum seekers.

The proposal, which has not been formally made by the U.S., would involve Mexico being designated a “safe third country” for the immigrants, meaning that refugees passing through Mexico to the U.S. would first have to claim asylum in Mexico. The U.S. has a similar agreement with Canada.