"Something has to be done about it," Trump said as he met with Chinese President Xi Jinping. In a separate meeting with Japanese Prime Minister Shinzo Abe, Trump said the two were tackling "the problem and menace of North Korea."

The White House said after the meeting with Abe that the U.S. was "prepared to use the full range of capabilities" in defense of Japan. Trump and Abe committed, the White House said, "to redoubling their efforts to bring all nations together to show North Korea that there are consequences for its threatening and unlawful actions."

The Trump administration has tried to press Beijing to rein in North Korea, a major trading partner of China, and halt Kim Jong Un's development of nuclear weapons before they can threaten U.S. territory. Trump has voiced his frustration in recent days that China hasn't done more, suggesting he may take steps of his own.