The United States has successfully carried out its first-ever missile defence test, with an exercise involving a simulated attack on California by an intercontinental ballistic missile (ICBM).

The test, at Vandenberg Air Force Base, began around 1pm local time (9pm UK). An hour later it was reported to have been a success.

It is designed to reassure a wary America, in the face of ever-growing threats from North Korea. Pyongyang has test-fired three ballistic missiles in three weeks, in an apparent demonstration of its resolve to bolster its nuclear and missile arsenals to deal with what it calls US military threats.