USAF Vanderberg air base successfully test-launched unarmed Minuteman III ICBM.

"There was a slight delay due to some instruments downrange but it went within the launch window," said Carla Pampe, chief of civic outreach for US Air Force Global Strike Command.

According to the Air Force, the missile carried an experimental re-entry vehicle headed for the designated target area in the Marshall Islands, 4,200 miles (6760 km) away in the Atlantic Ocean.

The Vandenberg facility is routinely used by the Air Force to test Minuteman missiles.

“While ICBM launches from Vandenberg Air Force Base almost seem routine, each one requires a tremendous amount of effort and absolute attention to detail in order to ensure a safe and successful launch," Colonel J. Christopher Moss, 30th Space Wing commander, said.

"This specific test will provide accuracy and reliability data that is essential to on-going and future modifications to the weapon system, which are key to improving the already impressive effectiveness of the Minuteman III force," he added.

The missile, manufactured by Boeing, is the only land-based ICBM in service in America and its development began in mid-1950s with the specific intent of attacking hardened military targets, specifically those in the former Soviet Union.

The latest version, Minuteman III, with an operational range of 13,000 km entered service in 1970.