North Korea's state media says its military has tested a new high-performance rocket engine, reports BBC.
Leader Kim Jong Un declared the test "a new birth" for the North's rocket industry, state news agency KCNA said.
He said the engine would help North Korea achieve world-class satellite launch capability, it added.
The development, not confirmed elsewhere, comes as US Secretary of State Rex Tillerson visits China - Pyongyang's main ally.
After personally overseeing the test, Mr Kim "emphasized that the world will soon witness the great significance of the epoch-making victory we achieved today", KCNA reported, adding that it marked the birth of the country's rocket industry.
Mr Tillerson's East Asian tour has been dominated by anxieties over North Korea's nuclear capabilities.