The U.S. Supreme Court was set on Tuesday to hear a bid by two American gun companies to throw out the Mexican government's lawsuit accusing them of aiding illegal firearms trafficking to drug cartels and fueling gun violence in the southern neighbor of the United States.

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.