The US Air Force tested a ground-launched ballistic missile from a California base over the Pacific Thursday, the second such test of the country's nuclear missile force in less than three months.

The Air Force launched the conventionally configured missile from Vandenberg Air Force Base northwest of Los Angeles at about 8:30 am local time (1630 GMT), according to a base spokesperson.

On October 2, the Air Force launched an unarmed Minuteman 3 intercontinental ballistic missile from Vandenberg, delivering a test reentry vehicle to the Kwajalein Atoll 4,200 miles away in the western Pacific.

No specific reason was given for Thursday's test, generally seen as demonstrating the operational capability of the US nuclear missile defense system. But it came as nuclear-armed North Korea has hinted that it could undertake its own ballistic missile test within weeks as a "Christmas gift" if the US does not come up with concessions in bilateral relations by the end of the year.