The United States said Tuesday it was reviewing the previous administration's withdrawal from the Open Skies Treaty as Russia moved formally to leave the post-Cold War accord meant to build trust.

The United States officially left the pact in November after former president Donald Trump's administration said Russia was violating the agreement that allows the two powers and their allies to monitor one another's airspace.

The administration of President Joe Biden said it was taking another look in consultation with US allies.

"We haven't made a decision on the future of American participation in the Open Skies Treaty. We are actively reviewing matters related to the treaty," State Department spokesman Ned Price told reporters.

"Russia's own continuing non-compliance with the treaty is one of several pertinent factors as we take stock of things," he said.

Russian Sukhoi jet fighters fly over the Kremlin and Red Square during rehearsals for the Victory Day military parade as Moscow prepares to exit the Open Skies Treaty trashed by former US president Donald Trump
Russian Sukhoi jet fighters fly over the Kremlin and Red Square during rehearsals for the Victory Day military parade as Moscow prepares to exit the Open Skies Treaty trashed by former US president Donald Trump AFP / Alexander NEMENOV

"As this process continues, we encourage Russia to take steps to come back into compliance with the treaty."

Moscow announced in mid-January it would leave the treaty, saying there was no progress in making it work in light of the US withdrawal.

A government database showed on Tuesday that President Vladimir Putin has submitted the bill exiting the treaty to parliament.

A note accompanying it said the treaty had helped "to significantly strengthen trust in the defense sphere," adding that the US withdrawal "upset the balance of interests" of signatory states.

"Serious damage has been dealt to the observance of the treaty and its role in strengthening trust and transparency," the note also said, adding that as a result Russia's national security was under threat.

Biden took office vowing a firmer line on Russia but has also been more open to international accords after Trump dumped a slew of agreements.

US State Department Spokesman Ned Price, seen in March 2021, says the United States is reviewing the Open Skies Treaty trashed by former president Donald Trump
US State Department Spokesman Ned Price, seen in March 2021, says the United States is reviewing the Open Skies Treaty trashed by former president Donald Trump POOL / MANDEL NGAN

Days after entering office, Biden extended by five years the New START nuclear treaty -- the last remaining arms reduction pact between the former Cold War rivals.

Open Skies was signed soon after the dissolution of the Soviet Union in 1992 and came into force in 2002.

The treaty allowed its nearly three dozen signatories to carry out short-notice flights over one another's territory to monitor potential military operations.

Members include countries across Europe, the former Soviet Union and Canada.

Moscow and Washington had long accused each other of breaching the terms of the agreement and Trump was reportedly outraged by a Russian flight over his New Jersey golf course.

The pact also allows its members to request copies of images taken during surveillance flights carried out by other members.

The country under surveillance is given 72 hours' warning ahead of a flight and 24 hours' notice of the flight path, to which it can suggest modifications.

The Open Skies pact was one of several major treaties Washington abandoned under Trump.

He also pulled out from the Intermediate-Range Nuclear Forces Treaty with Russia, further straining already tense relations between Moscow and Washington that in recent years have reached their lowest point since the end of the Cold War.