North Korea's state media says the country's military has tested a new high-performance rocket engine.
Leader Kim Jong Un said the test was "a new birth" for the North's rocket industry, state news agency KCNA said.
He said the engine will help North Korea achieve world-class satellite launch capability, it added.
The move comes as US Secretary of State Rex Tillerson is visiting China, which is Pyongyang's biggest ally and supporter.
After personally monitoring the test, Mr Kim apparently "emphasized that the world will soon witness the great significance of the epoch-making victory we achieved today," KCNA added.
Mr Tillerson's tour of East Asia has been dominated by tensions over North Korea's nuclear capabilities.