President Vladimir Putin on Thursday signed a bill revoking Russia’s ratification of a global nuclear test ban, a move that Moscow said was needed to establish parity with the United States.

Putin has said that rescinding the ratification of the Comprehensive Nuclear Test Ban Treaty, also known as the CTBT, would “mirror” the stand taken by the US, which has signed but not ratified the nuclear test ban. Both houses of the Russian parliament voted last month to revoke Moscow’s ratification of the bill.