Kim Jong-un supervises a missile test in North Korea, August 2019 (Picture: KCNA)
North Korea has said it carried out a "very important test" at its long-range rocket launch site that it reportedly rebuilt after having partially dismantled it when it entered denuclearization talks with the United States last year.
This signals that it is unlikely any further talks with the US will happen.
An unidentified spokesman from the North's Academy of National Defence Science said that the test would have "an important effect on changing the strategic position of [North Korea] once again in the near future".
Pyongyang did not say what the test included.
Analyst Kim Dong-yub, at Seoul's Institute for Far Eastern Studies, said North Korea likely tested for the first time a solid-fuel engine for an intercontinental ballistic missile.
The use of solid fuel increases a weapon's mobility.
Earlier in the week, CNN reported that a new satellite image indicated North Korea may be preparing to resume testing engines used to power satellite launchers and intercontinental ballistic missiles at the site.
The White House then released a statement saying that President Donald Trump and South Korean President Moon Jae-in are committed to continuing close communication regarding developments related to North Korea.
Mr Moon's office also released a similar statement, saying the two leaders had a 30-minute phone conversation at Mr Trump's request.
North Korea has said its satellite launches are part of its peaceful space development program.
But many outside experts say ballistic missiles and rockets used in satellite launches share similar bodies, engines, and other technology.
None of North Korea's three intercontinental ballistic missiles (ICBM) tests in 2017 was conducted at the Sohae site, but observers said the site was used to test engines for ICBM.