The U.S. test fired an unarmed Minuteman III missile Friday as a message to nations like Russia, China and North Korea that the country holds a stockpile of operational missiles. The missile was launched from the Vandenberg Air Force Base in California and landed close to the Kwajalein Atoll in the South Pacific.

"That's exactly why we do this. We and the Russians and the Chinese routinely do test shots to prove that the operational missiles that we have are reliable. And that is a signal ... that we are prepared to use nuclear weapons in defense of our country if necessary," said Deputy Defense Secretary Robert Work, who witnessed the launch, reporterd Reuters.

"We do it to demonstrate that these missiles -- even though they're old - they still remain the most effective, or one of the most effective, missiles in the world," Work added, according to the Los Angeles Daily News.

The Minuteman III, manufactured by Boeing, came into operation for the first time in 1970 and had an original expected life-span of 10 years. The Air Force has 450 Minuteman missiles, with 150 at each of three missile fields in Wyoming, Montana and North Dakota. Since the missiles are so old, a sample is tested each year to check for efficacy.

Technically called the LGM-30G Minuteman intercontinental ballistic missile, the Minuteman is controlled by the Air Force Global Strike Command and is an integral part of the U.S.' strategic deterrent forces, according to military.com.