Russia's top military officer has threatened to attack the U.S.-led European missile defense shield if the project goes ahead.

Chief of General Staff Nikolai Makarov said Thursday he would launch a pre-emptive strike against missile shield facilities, which are planned in Poland, Turkey and Romania.

Makarov's threat follows that of President Dmitry Medvedev, who last year said Russia would attack the shield if an agreement with the U.S. and NATO was not reached.

A decision to use destructive force pre-emptively will be taken if the situation worsens, Makarov said, according to the AP.

NATO and the U.S. claim the shield's ground and ship-based radar and interceptor missiles, which are due to be installed in four phases by 2020, are solely intended to counter the threat from Iranian missile attacks.

But Russia rejects the claims, saying the shield will eventually become powerful enough to nullify the country's nuclear deterrent.

The Kremlin said it would use the results of computer modellng to show how NATO missile defense facilities ... may affect Russia's forces of nuclear deterrence, Deputy Defense Minister Anatoly Antonov told the government daily Rossiiskaya Gazeta, Reuters reported.

We would like to explain, in language that is clear to military and technical experts, what consequences implementation of the U.S. and NATO missile defense plans will lead to, Antonov said.

Russia has previously offered to run the shield jointly with NATO, an idea rejected by the alliance.

On Thursday, Russia's Security Council Secretary Nikolai Patrushev reiterated the offer, saying that a joint operation of the shield could strengthen security of every single country of the continent and would be adequate to possible threats and will not deter strategic security.

The Kremlin has sought guarantees the shield is not directed at Russia, threatening to retaliate of an agreement is not reached.

In 2009, U.S. President Barack Obama tried to ease tensions by adapting the shield to include shorter-range interceptor missiles, an offer Russia initially warmed to.

But after suggesting the shield could be upgraded to counter its own missiles, the Russians threatened to target the shield's facilities, recently commissioning a radar station near the Polish border in Kaliningrad that is capable of tracking missile launches from Europe.