Remarks by a top administration official appeared to be aimed at dispelling skepticism of its assertions, as President Donald Trump vows to restart U.S. tests.

WASHINGTON — The United States is ready to carry out low-yield nuclear tests to match alleged secret explosions by China and Russia, ending a decades-old moratorium, a senior official said Tuesday.

At a event in Washington D.C., A U.S. official said a remote earthquake in 2020 was caused by a Chinese nuclear test.

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

New START, the last treaty between the United States and Russia that limited deployment of nuclear warheads, expired this ...

The United States on Friday accused China of carrying out a secret nuclear test in 2020 as the Trump administration calls for ...

When the first nuclear bomb test took place 80 years ago, the scientists who gathered to observe the explosion in the New Mexico desert recognized they were playing with fire. Physicist Enrico Fermi ...

A top arms diplomat at the State Department recently laid out what might come next as Washington upends decades of federal policies on nuclear proliferation.

HIROSHIMA, Japan — Shortly before the 80 th anniversary of nuclear attack on Hiroshima early this month, several dozen elementary school students met with atomic bomb survivor and farmer Toshiyuki ...