U.S. forces would defend democratic Taiwan in the event of a Chinese invasion, President Joe Biden said in an interview broadcast Sunday — his fourth and most explicit statement on the issue since taking office.

Asked in an interview with CBS’s “60 Minutes” program if the U.S. military would defend the island, Biden said, “Yes, if in fact there was an unprecedented attack.”

Asked to further clarify if he meant that, unlike in Ukraine — where Washington has sent billions of dollars in weapons and aid — U.S. troops would defend Taiwan in the event of an invasion, Biden offered an unequivocal “Yes.”