North Korea says it has test-fired a new type of "tactical guided weapon", its first such test in nearly half a year, and demanded that Washington remove secretary of state Mike Pompeo from nuclear negotiations.
If correct, it would be the first test since denuclearisation talks between US President, Donald Trump, and leader of North Korea, Kim Jong-un ended without an agreement and comes after the release of images showing movement at North Korea's main nuclear site.
The test, which did not appear to be of a banned mid or long-range ballistic missile that could scuttle negotiations, allows Pyongyang to show its people it is pushing ahead with weapons development while also reassuring domestic military officials worried that diplomacy with Washington signals weakness.
In a separate statement, Pyongyang's foreign ministry accused Mr Pompeo of playing down the significance of comments by North Korean leader Kim Jong-un, who said last week that Washington has until the end of the year to offer mutually acceptable terms for an agreement to salvage the high-stakes nuclear diplomacy.
The demand for Mr Pompeo's removal from the talks and the weapon test point to Pyongyang's displeasure with the deadlocked negotiations.
Mr Kim observed the unspecified weapon being fired on Wednesday by the Academy of Defence Science, the North's state-run Korean Central News Agency said.
Mr Kim was reported to have said: "The development of the weapon system serves as an event of very weighty significance in increasing the combat power of the People's Army."
The Associated Press could not independently verify North Korea's claim, and it was not immediately clear what had been tested.
A ballistic missile test would jeopardise the diplomatic talks meant to provide the North with concessions in return for disarmament.
The test comes during an apparent deadlock in nuclear disarmament talks after the failed summit in Hanoi between Mr Kim and President Donald Trump earlier this year.
Some in Seoul worry that the North will turn back to actions seen as provocative by outsiders as a way to force Washington to drop its hardline negotiating stance and grant the North's demand for a removal of crushing international sanctions.
A string of increasingly powerful weapons tests in 2017 and Mr Trump's response of "fire and fury" had many fearing war before the North shifted to diplomacy.
Darya Dolzikova, from the Royal United Services Institute, said: "I think Kim is messaging to the local population that despite everything that's been happening, or not happening, between him and Trump, that he still stands strong on the defence of the country, on the support of the military, the armed forces.
"At the same time, it is very much a message to the United States that they are not necessarily playing around; that they will start to push buttons if they have to."
During a speech in Texas on Monday, Mr Pompeo said Mr Kim promised to denuclearise during his first summit with Mr Trump and that US officials were working with the North Koreans to "chart a path forward so we can get there".
"He (Kim) said he wanted it done by the end of the year," Mr Pompeo said. "I'd love to see that done sooner."
Meanwhile, the Kremlin said Mr Kim will visit Russia later this month.
It said in a brief statement that Mr Kim will visit Russia "in the second half of April" on Russian President Vladimir Putin's invitation.
Russian media have been abuzz in recent days with rumours about the rare meeting between the leaders.
Mr Putin is set to visit China later this month, and some media speculated that he could meet with Mr Kim in Vladivostok, the port city near the border with North Korea.