The US military has deployed a ground-based missile interceptor in Alaska, the first of a national defense system designed to shoot down enemy missiles, local media reported Friday.

The nearly 17-meter-long three-stage interceptor was installed Thursday by military personnel at Fort Greely.

By the end of the year, five more interceptors will be installed in Alaska, and four will be deployed at Vandenberg Air Force Base in California. Ten more will be installed at Fort Greely by late 2005.

The Bush administration has planned to deploy a preliminary missile defense system of six rocket interceptors in Alaska and four in California by the end of September, saying the United States needs such a system to guard against long-range missile attacks.

The US Congress has appropriated over 10 billion US dollars for the missile defense system for fiscal 2005, and the Missile Defense Agency estimated the system would cost as high as 53 billion dollars for 2004-2009.