WASHINGTON: The United States announced Wednesday that a planned test of an unarmed intercontinental ballistic missile had been called off before launch, adding that an investigation was under way to determine what went wrong.

The US Air Force said in a statement that it was assessing its options to reschedule the launch, one of a series of regular tests aimed at demonstrating the effectiveness of Washington’s nuclear arsenal and reassuring America’s allies.

“An unarmed Minuteman III intercontinental ballistic missile test launch from Vandenberg Air Force Base, California, experienced a ground abort prior to launch,” the statement said. “The cause of the ground abort is currently under investigation.”