Russia’s President Vladimir Putin has revoked his country’s ratification of the Comprehensive Nuclear Test Ban Treaty (CTBT), a move he says is designed to bring Moscow into line with the United States.

The signing of the new law to abandon the landmark agreement outlawing nuclear weapons tests came on Thursday, a week after Russia’s upper house Federation Council unanimously approved it.

The lower house State Duma had passed the bill in an accelerated vote before this. With Putin’s signature, the legislation came into effect on Thursday.

The 1996 treaty outlaws all nuclear explosions, including live tests of nuclear weapons, though it was never effective because some key countries did not ratify it.

Moscow on October 6 announced its intention to withdraw from the treaty to “mirror” the position of the US, which has signed, but not ratified the treaty.

It is unclear, however, whether the revocation will result in Russia resuming tests of nuclear weapons.

Putin said on October 5: “I hear calls to start testing nuclear weapons. I am not ready to say whether we really need to conduct tests or not.”

Deputy Foreign Minister Sergei Ryabkov said earlier this month that Moscow would continue to respect the ban and would resume nuclear tests only if the US does so.

“As our president said, we must be on alert, and if the United States moves towards the start of nuclear tests, we will have to respond here in the same way,” the official said.

Just hours after the upper house vote, Russia’s military conducted a “massive” retaliatory nuclear strike drill.

The exercise, which involved the test launch of missiles from a land-based silo, a nuclear submarine and a long-range bomber aircraft, was overseen by Putin.

‘Disturbed’

The US stated earlier this month that it was “disturbed” by Russia’s move to revoke the CTBT ratification.

“A move like this by any state party needlessly endangers the global norm against nuclear explosive testing,” the US Department of State said.

Russia should not be “wielding arms control and irresponsible nuclear rhetoric in a failing attempt to coerce other states”, the State Department added, appearing to suggest that the move was aimed at pressuring the US and other countries which are supporting Ukraine in its fight against Russian forces.

Since invading the neighbouring country, Putin has repeatedly invoked Russia’s nuclear doctrine.

With the abandonment of the CTBT, the last remaining bilateral nuclear weapons treaty between Washington and Moscow is New START, under which the pair used to regularly inspect each other’s nuclear facilities and limit warheads.

Russia suspended the treaty in February. It is due to expire in early 2026.

Ryabkov said last week that the Kremlin had received informal proposals from the US to resume talks on issues of strategic stability and arms control “in isolation from everything that is happening”.