Russian President Vladimir Putin on Thursday signed a law revoking Russia's ratification of the Comprehensive Nuclear Test Ban Treaty, a move strongly criticised by the United States.
The 1996 treaty outlaws all nuclear explosions, including live tests of nuclear weapons, though it never came into force because some key countries -- including the United States and China -- never ratified it.
US Secretary of State Antony Blinken criticised Putin's announcement on Thursday, and called on Moscow to commit to not carry out testing.
"Unfortunately, it represents a significant step in the wrong direction, taking us further from, not closer to, entry into force" of the treaty, Blinken said in a statement.
"This continues Moscow's disturbing and misguided effort to heighten nuclear risks and raise tensions as it pursues its illegal war against Ukraine," he said.
Putin last week oversaw ballistic missile drills in what Defence Minister Sergei Shoigu said was practice for a "massive" retaliatory nuclear strike against an unnamed enemy.
The bill to revoke the treaty passed through Russia's parliament last month in a fast-track process.
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