The U.S. Under Secretary of State for Arms Control and ‌International Security Thomas DiNanno told delegates at ​the Disarmament ‌Conference in Geneva ‍that ⁠extending new START - which set limits on the world's two biggest nuclear powers the United States and Russia - would not benefit the U.

The US accused China of secret nuclear tests, banned under international agreement, that were building toward tests of larger nuclear warheads.

If nothing replaces the New START nuclear arms treaty, security analysts see a more dangerous environment with a higher risk of miscalculation.

The U.S. State Department accused the Chinese government on Friday of conducting a secret nuclear test in 2020, while the Trump administration is seeking to include Beijing in new nuclear arms control agreements.

The United States on Friday urged three-way talks with Russia and China to set new limits on nuclear weapons, as it accused Beijing of conducting secret nuclear tests and dramatically

The United States on Friday accused China of carrying out a secret nuclear test in 2020 as the Trump administration calls for a broader nuclear weapons agreement including both China and Russia.

The United States on Friday urged three-way talks with Russia and China to set new limits on nuclear weapons, as it accused Beijing of conducting secret nuclear tests and dramatically swelling its arsenal.

The US accused China Wednesday of conducting at least one secret nuclear test as Washington continued its push for a new arms control treaty that would include Beijing in addition to Moscow and Washington.