Russia suspended participation in 2007, protesting at NATO nations’ refusal to ratify the new version and complaining that the pact was outdated because several former Warsaw Pact states had since joined NATO.

The NATO nations’ refusal to ratify stemmed from earlier disputes with Russia over deployments in Georgia and Moldova.

The United States said last year it would no longer provide Russia with annual notifications or military data called for in the treaty, but that it hoped Moscow would eventually return to the pact.