North Korea has tested a new type of high-thrust engine, with leader Kim Jong Un hailing it as "a historic day which can be called 'March 18' revolution'."
The test comes as US Secretary of State Rex Tillerson wraps up a three-country visit to East Asia which has focused on containing North Korean aggression.
The new rocket marked the "new birth of the Juche-based rocket industry" state-run news agency KCNA reported, adding that it would help consolidate the country's technological foundation in "world-level" satellite delivery capability.
"Juche" is North Korea's homegrown ideology and the word itself translates as "self-reliance".
Kim, who personally supervised the test, said that "the whole world will soon witness what eventful significance the great victory won today carries," according to KCNA.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
North Korea is believed to be trying to develop a nuclear missile that could reach the United States.
Almost two weeks ago it carried out a missile launch exercise it said was targeting US bases in Japan, and in his New Year's address, Kim said Pyongyang was almost ready to test-fire an intercontinental ballistic missile.
During diplomatic meetings in Japan and South Korea this week, Tillerson called for tougher sanctions on Pyongyang and said the US would not rule out military action against the country.
He also said Washington would not resume talks with North Korea unless it first agreed to get rid of its nuclear arsenal.
