He added, however, that “while we strive for cooperation, we have also been frank in our discussions with Russia that we will continue to develop and deploy our missile defenses, irrespective of the status of missile defense cooperation with Russia.”

The United States and NATO say the shield will come into full operation by around 2020 and is to protect against “rogue” states such as Iran. But Russia insists the system is a threat to its national security and is seeking written guarantees from NATO that it will not be used against Russia’s strategic nuclear deterrent.

Russia’s military and political leadership have repeatedly warned their western partners that if talks fail, Moscow may take a series of measures including deployment of Iskander short-range nuclear-capable ballistic missiles in the Kaliningrad exclave.

Earlier this month, Russia’s Chief of the General Staff Nikolai Makarov did not rule out delivering preemptive strikes against NATO missile defense systems in Europe if current deployment plans go ahead.

Speaking at a missile defense conference in Moscow, he said “taking into account the destabilizing nature of the missile defense system... the decision on the pre-emptive use of available weapons will be made during an aggravation of the situation.”

Gordon reiterated on Thursday that the missile shield would not threaten Russia.

“Let me be clear: NATO is not a threat to Russia nor is Russia a threat to NATO,” he said.

He also added “it's no secret that there are issues on which the allies and Russia differ. Russia has been critical of NATO's operation in Libya; we also disagree fundamentally over the situation in Georgia.”

Russia recognized two breakaway Georgian republics, Abkhazia and South Ossetia, as independent states, following a brief war with Georgia in August 2008. The United States and the European Union have strongly opposed the move.