US President Donald Trump and South Korean President Moon Jae-In on Sunday agreed that North Korea "poses a grave and growing direct threat," in a phone call one day after the UN Security Council backed fresh sanctions on the North.

"The two leaders affirmed that North Korea poses a grave and growing direct threat to the United States, South Korea, and Japan, as well as to most countries around the world," the White House said of the call, in which the pair welcomed the sweeping sanctions.

"The leaders committed to fully implement all relevant resolutions and to urge the international community to do so as well."