A NATO official said Tuesday a joint anti-missile system proposed by Russia was impossible but Moscow should connect its missile defense system to that of the Western alliance.

NATO rejected the Russian proposal because it could not entrust its security to third countries, said James Appathurai, the NATO secretary general's special representative to the Caucasus and Central Asia, in an interview with Interfax news agency.

Moscow has long opposed the deployment of NATO missile defense facilities near its borders, saying they would be a security threat to the country and upset the strategic balance of force in Europe.

Russia has also long sought a legal guarantee from Washington and NATO that the NATO missile defense system was not targeting Russia.

But Appathurai said, if Russia connected its missile defense system to NATO's, it would get an "ultimate 100 percent guarantee."

He said the U.S.-led NATO system could not pose any threat to Russian strategic missiles for obvious technical reasons.

"We make it clear that it (the anti-missile defense system) has no technical capabilities to interrupt Russia's capability to counter a nuclear strike," Appathurai said.