Russia has officially suspended participation in a major Cold War arms treaty but says it will continue talks with western partners on resuming it.

The Russian Foreign Ministry said in a statement Wednesday that the decision to temporarily back out of the Conventional Forces in Europe Treaty was prompted by what it termed "exceptional circumstances."

A U.S. State Department spokesman, Sean McCormack, calls Russia's action disappointing and wrong.

The Organization for Security and Cooperation in Europe wants Russia to reconsider. Spanish Foreign Minister Miguel Angel Moratinos, the current OSCE chairman, called the treaty a cornerstone of European stability.

The Soviet Union and NATO signed the treaty limiting conventional weapons deployment in 1990. It was updated in 1999 after the collapse of the Soviet Union.

Russia ratified the updated treaty in 2004. But NATO refuses to follow until Russia fulfills its commitment to withdraw forces from former Soviet bases in Georgia and Moldova.

Moscow calls those deployments peacekeeping missions and refuses to withdraw its troops. Russia also objects to U.S. plans for deploying a missile defense system in central Europe, saying it undermines Russia's security.

U.S. officials say the system is designed to protect NATO countries from possible missile attacks from Iran.

Russia says the CFE moratorium does not involve a substantial regrouping of troops and hardware to the West and elsewhere other strategic directions. It says the step is aimed at getting other member nations to take into account Russia's concerns.

Some information for this report provided by AFP and Reuters.