Russia's State Duma, the lower house of parliament, has voted to withdraw the country from an international treaty allowing surveillance flights over military facilities following the departure from the accord by the United States late last year.
The May 19 vote to exit from the Open Skies Treaty must still be endorsed by the upper house of parliament and signed by Russian President Vladimir Putin to take effect.
The Open Skies Treaty was signed in 1992 and entered into force in 2002, allowing its 34 members to conduct short-notice, unarmed observation and surveillance flights over one another's territories to collect data on military forces and activities. More than 1,500 flights have taken place under the agreement.
The United States formally withdrew on November 22, 2020, from the arms-control and verification agreement that Washington repeatedly said Moscow "flagrantly violated," six months after giving notice of the pending exit.
The U.S. move was another blow to the system of international arms control that former U.S. President Donald Trump had repeatedly scorned, complaining that Washington was being either deceived or unfairly restrained in its military capabilities.
U.S. media have reported that the administration of President Joe Biden, who replaced Trump at the White House in January, is hesitant to consider rejoining the accord since it would send the "wrong signal" to Moscow, though no final decision has been made on the issue.
Biden is reportedly concerned that agreeing to rejoin a treaty that Washington feels Russia continues to violate would also undermine his position on the broader arms control agenda.
The treaty's proponents say the flights help build confidence by showing that, for example, adversaries are not secretly deploying forces or preparing to launch attacks and Moscow has signaled its readiness to reverse the withdrawal procedure and stay in the treaty if the U.S. returns to the agreement.