A new U.S. test aimed to intercept a supposed enemy long-range missile over the Pacific failed on Friday, agencies reports said.

"The target did not reach sufficient altitude to be deemed a threat and so the Ballistic Missile Defense System did not engage it, as designed," Missile Defense Agency Director Henry Obering was quoted as saying.

During the test, the target missile launched from Alaska failed to reach the test area before an interceptor missile could be launched from California.

The U.S. military is still trying to find out why the target, an old intercontinental ballistic missile, failed after launch from Kodiak Island in Alaska.

The interceptor was supposed to try to collide with the target high over the Pacific.

The Missile Defense Agency described the test as "not completed," avoiding to use the term "failure" and saying it will try again some time in the summer.

At present, the United States has two ground sites hosting missile interceptors, in California and Alaska, respectively.

Since last year, the Bush administration has been negotiating with several European allies to find a third site for its ground-based interceptor missiles.