The US has successfully shot down an intercontinental ballistic missile, during the first-ever defence test of its kind.
Officials said the test of the Ground Based Midcourse Defence (GMD) system at Vandenberg Air Force Base in California was successful.
Pentagon officials said the test aimed to simulate the capability for responding to a hypothetical North Korean Intercontinental Ballistic Missile (ICBM).
Vice Admiral Jim Syring, director of the Pentagon agency in charge of developing the missile defence system, said it was "an incredible accomplishment."
"This system is vitally important to the defence of our homeland, and this test demonstrates that we have a capable, credible deterrent against a very real threat," he said.
Intercontinental Ballistic Missile
The ICBM was launched from Kwajalein Atoll in the Pacific and was equipped with a warhead which would approximate the qualities of a nuclear warhead.
The GMD interceptors carry no warheads themselves but rely on the kinetic energy of their impact to destroy the incoming missile.
Kinetic energy hits are intended to minimise the risk of detonating conventional warheads, including nuclear tipped ballistic missiles.
It is a similar missile defence system to the Terminal High Altitude Area Defence (THAAD) system, which was recently deployed in South Korea.
Diplomatic tension
North Korea's ballistic missile tests have created tensions between Pyongyang and Washington, with Kim Jong-Un featuring commonly in discussions between President Donald Trump and Chinese counterpart Xi Jinping.
The California test came as the US ambassador to the UN said the Trump administration believed Beijing was using back channels with North Korea in an attempt to get it to stop missile and nuclear tests.
Despite UN and unilateral sanctions, North Korea has continued with its missile tests. It has argued the sanctions are an infringement of its right to self-defence.
The country’s most recent test of a medium-range Scud missile was claimed as a success, although its ability to launch a ballistic missile capable of hitting intercontinental targets has been disputed.
The state has stressed that it will continue to develop a pre-emptive strike capability.