The dispute between Russia and NATO over the U.S.-led missile defense system in Europe is holding back their planned cooperation, a senior NATO official here said Tuesday.

"It would be wrong to tie all of our diverse and successful relations to this problem or make it a cornerstone," head of NATO's Moscow information bureau Robert Pszczel told Interfax news agency.

He said the two sides had agreed on cooperation in other areas, which were as important as the missile defense issue.

"We should not get stuck on it. Indeed, there are disagreements over this (missile) issue, but it is being discussed because everyone is aware of its importance," Pszczel said.

Meanwhile, Pszczel said Russia's deployment of its new S-400 air defense missile systems in Kaliningrad, the westmost exclave of Russia, would not help promote cooperation between the two sides.

"NATO has already stressed ... we are building an exclusively defensive, not offensive, missile defense shield. Russia, for its part, plans to deploy missiles that could pose threats which are out of the question as far as we are concerned," Pszczel said.

He said the sides needed to take advantage of all possible contacts to continue their talks over the disagreements.

Moscow has long opposed the deployment of missile defense facilities near its borders and wants legally binding guarantees from the United States and NATO that the system will not target Russia.

President Dmitry Medvedev warned last November that Russia might station missile defense systems, including the Iskander, in western and southern parts of the country if there were any additional U.S. missile deployments in Europe.