Moscow, Jun 19 (IANS): Russia will officially withdraw from the Treaty on Open Skies, an arms control pact with the US that permitted unarmed surveillance flights over military facilities in both countries, on December 18, the Foreign Ministry said.

In a statement on Friday, the Ministry announced that it notified all the related parties of Russia's pullout and the decision will enter into force in six months, reports Xinhua news agency.

The Ministry recalled Russia's efforts to preserve the arms-control pact and reiterated that the US is responsible for its collapse.

On June 7, President Vladimir Putin signed the law to quit the Treaty on Open Skies.

The administration of former US President Donald Trump announced a year ago that Washington would withdraw from Open Skies, alleging Russia had violated its terms.

The incumbent Joe Biden administration decided in May to stick to that decision.

Russia blamed the US for the end of the agreement, which was signed in Helsinki on March 24, 1992.

It has been in force since 2002.

Only one key arms control agreement remains between the US and Russia -- the New START nuclear disarmament treaty.

Shortly before it was set to expire in February, Biden and Putin had agreed on an extension.

The New START treaty limits the nuclear arsenals of both countries to 800 delivery systems and 1,550 ready-to-use nuclear warheads.