North Korea's state media says its military has tested a new high-performance rocket engine.
Leader Kim Jong Un attended the test at the Sohae launch site, according to a report by the Korean Central News Agency, which added the test was intended to confirm the engine’s thrust power and gauge the reliability of its control system and structural safety.
The report Sunday said the test was a success.
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.
In South Korea on Friday, he said a US military response would be on the table if North Korea threatened South Korea or US forces.
North Korea has conducted five nuclear tests and a series of missile launches. Experts and government officials believe it is working to develop nuclear-warhead missiles that can reach the US.
Kim Jong Un has said the country is close to a test-launch of an intercontinental ballistic missile.