A U.S. official focusing on arms control has provided what he called new, declassified details of a Chinese underground nuclear test nearly six years ago.

The U.S. government revealed new intelligence on Tuesday suggesting China may have conducted an ...

Remarks by a top administration official appeared to be aimed at dispelling skepticism of its assertions, as President Donald ...

President Donald Trump’s call for the United States to resume testing of nuclear weapons last week has experts scratching their heads. What did he really mean – exploding a warhead or testing delivery ...

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 ...

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

President Donald Trump wrote on Truth Social, his social media site, that he had instructed the Department of War (formerly the Defense Department) to return to “nuclear testing” — although it’s ...