WASHINGTON • North Korea has carried out another test of a rocket engine that American officials believe could be part of its programme to develop an intercontinental ballistic missile (ICBM), officials have told Reuters.

The latest test follows one earlier this month, and is another sign of Pyongyang's advancing weapons programme. It comes amid mounting United States concerns about additional missile and nuclear tests, potentially in the near future.

Several US officials, speaking on condition of anonymity, said the second test took place last Friday night and the engine could possibly be used in an ICBM.

Earlier this month, North Korean leader Kim Jong Un said his country had conducted a test of a new high-thrust engine at the Tongchang-ri station, saying it was "a new birth"of its rocket industry.

At the time, North Korea's official media said the engine would help it achieve world-class satellite launch capability, indicating the test was of a new type of rocket engine for long-range missiles.

Mr Kim has also said North Korea is close to an ICBM test-launch.

North Korea has been testing rocket engines and heat shields for an ICBM while developing the technology to guide a missile after re-entry into the atmosphere following a lift-off, experts have said.

Once fully developed, a North Korean ICBM could threaten the continental US, which is around 9,000km from the North. ICBMs have a minimum range of about 5,500km, but some are designed to travel 10,000km or farther.

Pyongyang has conducted five nuclear tests and a series of missile launches in defiance of United Nations resolutions. US Secretary of State Rex Tillerson said during a recent visit to the region that a military response would be "on the table" if Pyongyang took action to threaten South Korea and US forces.

REUTERS