A U.S. official focusing on arms control has provided what he called new, declassified details of a Chinese underground ...

US intelligence agencies believe that China is developing a new generation of nuclear weapons and has conducted at least one covert explosive test in recent years as part of a broader push to ...

The allegations were leveled by U.S. officials late last week. Arms control experts worry that norms against nuclear testing are unraveling.

While China is expanding its nuclear arsenal at a dramatic pace, Russia and the U.S. are also testing new delivery platforms.

A US official has presented evidence of a secret Chinese nuclear test, raising tensions in global arms control discussions.

Scientific knowledge about the damaging effects of nuclear-weapons testing helped to end such tests. Those findings haven’t changed.

A US official says a seismic station in Kazakhstan collected evidence of an alleged China nuclear test at Lop Nur in June 2020.

US President Donald Trump has shocked the world by announcing another nuclear bomb test. There's no doubt that countries like China, North Korea, and Russia are secretly conducting nuclear tests.

Was President Trump’s recent directive to resume U.S. nuclear testing — after a hiatus of 33 years — an actual policy decision? Or was it a political stunt to project toughness? His surprise ...