An undersea earthquake off the coast of North Korea was not caused by a nuclear test, the South's media reported Thursday.
Washington's ambassador to the United Nations pledged Sunday.
The US Missile Defense Agency said Friday it would soon test an anti-ballistic missile system after North Korea demonstrated its arsenal was capable of striking parts of Alaska.
The United States led a push at the UN Security Council Wednesday for tougher sanctions on North Korea.
The UN Security Council will hold an emergency meeting on Wednesday
North Korea has test launched an intercontinental ballistic missile for the first time
President Donald Trump welcomed South Korea's Moon Jae-In to the White House.
The United States slapped unprecedented sanctions Thursday.
N.Korea delivered a rare statement at the UN Security Council, accusing the US of attaching conditions to its offer of talks on Pyongyang's military programs.
The tour agency that took US student Otto Warmbier to Pyongyang said Tuesday.