US President George W Bush says a missile defence system in Europe is urgent because Iran could be working on weapons capable of striking the United States.

The United States has rejected a Russian call to freeze a planned anti-missile defence system in central Europe, despite a warning from Russia that it would move to "neutralise" the threat from such a system.

Top level talks between Russia and the United States in Moscow have begun with a threat from Russian President Vladimir Putin to withdraw from a Cold War treaty on intermediate missiles.

U.S. Secretary of State Condoleezza Rice and Defense Secretary Robert Gates open strategic security talks in Moscow Friday with their Russian counterparts, in a push to narrow differences over U.S. missile plans in Europe.

The missile defense elements the U.S. plans to deploy in Poland could be used as shock weapons, and present a real threat to Russia, a Russian military expert said on Thursday.

The Parliamentary Assembly of the Council of Europe has cancelled a debate on U.S.' plans to deploy missile shield elements in Central Europe, fiercely opposed by Russia.

Moscow views the U.S. missile defense program in Central Europe as anti-Russian, but has sufficient capability to counter it, a top military official said Wednesday.

U.S. military experts have visited the Russian-operated Qabala (Gabala) radar station in Azerbaijan, which Moscow has offered to share with the United States to counter rogue missile threats.

Military experts from Azerbaijan, Russia, and the United States are to meet in Azerbaijan on September 18 to discuss the possibility of Washington using the country's Qabala (Gabala) radar station as part of its planned missile-defense shield.

The Russian and U.S. defense and foreign ministers will discuss the joint use of the Gabala radar Russia leases from Azerbaijan in October, the Russian ambassador to Azerbaijan said Thursday.

Azerbaijani-Russian-U.S. consultations on the joint use of the Gabala radar station that Russia leases from Azerbaijan will be held within a week, a spokesman for Azerbaijan's Foreign Ministry said Wednesday.

Russian President Vladimir Putin says it is still possible to reach a compromise with the United States over Washington's plans to locate parts of a missile-defense shield in Europe.