“You know we have a treaty with Japan where if Japan is attacked, we have to use the full force and might of the United States,” Trump said. “If we’re attacked, Japan doesn’t have to do anything. They can sit home and watch Sony television, OK?”

Trump said he had been told Japan pays “50 percent of the cost” of basing U.S. troops in Japan. “Why don’t they pay 100 percent?” he asked.

The GOP nominee went on to criticize his Democratic rival, Hillary Clinton, for her “dumb talk” on the U.S. commitment to its allies.

Clinton touted her experience as secretary of state in a June address, saying that as president she would maintain and foster U.S. alliances, including with Japan.

Trump slammed Clinton’s position Friday, saying the U.S. must be “prepared to walk” in negotiations to get countries to pay more for U.S. defense.

“It could be that Japan will have to defend itself against North Korea,” Trump said. “You always have to be prepared to walk. I don’t think we’ll walk. I don’t think it’s going to be necessary. It could be, though.”

The Republican nominee also suggested that Japan might be “better off” with its own atomic weapons, and that he would consider, as president, ending the U.S. defense commitment to Japan and encouraging them to “go nuclear.”