Russian President Vladimir Putin says his country is developing a new nuclear missile system unlike any possessed by other nuclear powers.

Mr. Putin told a meeting of high-ranking military officials today (Wednesday) that the system could be put into service in the coming years. He did not elaborate.

Mr. Putin said international terrorism is a major threat for Russia, and the country may face other dangers if it ignores defense components such as nuclear arms and a missile shield.

A State Department spokesman said the Bush administration is not alarmed by the Russian announcement. He said the modernization activities comply with obligations under a previous agreement (the Moscow treaty), which calls for the mutual reduction in strategic offensive weapons.

At the White House, spokesman Scott McClellan said Washington is well-aware of the long-standing military modernization program in Russia.