Story highlights The intercontinental ballistic missile traveled 4,200 miles

The US regularly tests its ICBM system to verify its accuracy and reliability

Washington (CNN) The Air Force on Wednesday launched its second test of a nuclear-capable long-range missile in a week, according to the Air Force Global Strike Command.

Launched from Vandenberg Air Force Base in California, the unarmed Minuteman III intercontinental ballistic missile traveled 4,200 miles to a test range near the Marshall Islands.

The US regularly tests its intercontinental weapon system to verify its accuracy and reliability -- with launches scheduled long in advance, according to defense officials.

Though considered by military officials to be fairly routine, the missile tests that took place Wednesday and on April 26 are notable in that they occurred amid rising tensions and military flexing over North Korea's nuclear program.

The Minuteman III is traditionally known as the only land-based leg to the US nuclear triad.

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