Top U.S. nuclear official confirms plans to restart American nuclear testing, citing a need to match covert tests by Beijing and Moscow.

GENEVA — The United States accused Beijing on Friday of conducting a secret nuclear test in 2020 as it called for a new, broader arms control treaty that would bring in China as well as Russia.

“Rather than extend “NEW START” (A badly negotiated deal by the United States that, aside from everything else, is being grossly violated), we should have our Nuclear Experts work on a new, improved, ...