President Trump is leaving the “nuclear” option on the table in dealing with increasingly hostile North Korea, the White House said Sunday.

Trump told Japanese Prime Minister Shinzo Abe that he is committed to “defending our homeland, territories, and allies using the full range of diplomatic, conventional, and nuclear capabilities,” according to a statement from the White House.

He was responding to reports that the hermit kingdom successfully tested a hydrogen bomb that could be mounted on the tip of an intercontinental missile.

Earlier in the day, Trump called the tests “hostile and dangerous.” Asked whether whether the U.S. would attack North Korea, Trump told reporters: “We’ll see.”