As President Donald Trump pressures Mexico to address the flow of migrants and drugs heading north into the United States, the Supreme Court is set to hear arguments Tuesday in a major appeal about one thing that’s crossing the border toward Mexico: guns.

While President Donald Trump has made a point of going after drug cartels, the Mexican government says U.S. gunmakers should be held liable for violence caused by their weapons in Mexico.

The dispute focuses on whether Mexico can hold U.S. manufacturers liable for gun violence and comes amid rising tensions between the countries.