NEW YORK - North Korea's claim that it successfully tested a hydrogen bomb prompted skepticism and some snark on social media on Wednesday, even as the development unnerved South Korea and Japan and ...

In northwest North Korea, Mount Mantap became the center of the country’s nuclear testing program between 2006 and 2017, when six underground detonations were carried out beneath the mountain. The ...

South Korea says abnormally high radiation levels were detected near the border between the two Koreas days after North Korea claimed to have mastered a complex technology needed to make a hydrogen ...

BEIJING (Reuters) - British Foreign Secretary Philip Hammond said on Wednesday a test of a hydrogen nuclear bomb by North Korea would be a "provocation which I condemn without reservation" and a ...

The White House says the U.S. government's early analysis of underground activity in North Korea "is not consistent" with that country's claim of having conducted a successful hydrogen bomb test.