North Korea has carried out another test of a rocket engine that U.S. officials believe could be part of its program to develop an intercontinental ballistic missile (ICBM), officials said Monday.

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

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