North Korea on Monday called US National Security Adviser John Bolton a "war monger" after he termed the North's recent missile tests a violation of UN resolutions.
In a statement, the North's foreign ministry said giving up missile tests would mean giving up the right to self-defence.
"His claim is indeed much more than ignorant," the unidentified spokesman said. "Our military drill neither targeted anyone nor endangered the surrounding countries, but Bolton makes dogged claims that it constitutes a violation of the 'resolutions', poking his nose into other's internal matters.
"It is not at all strange that perverse words always come out from the mouth of a structurally defective guy," the spokesman said.
The White House has played down the tests, with US President Donald Trump tweeting, "North Korea fired off some small weapons, which disturbed some of my people, and others, but not me."
Democrats and Republicans squared up on Wednesday for what could be two years of deadlock in Washington, with the resurgent Democrats vowing to use their resounding midterm election victory to rein in President Donald Trump, who signalled he was ready to continue flexing the executive branch's considerable powers.
NASA's Swift satellite telescope, which spent two decades studying the most powerful known blasts of energy in the cosmos, tumbled out of orbit as expected on Wednesday and burned up in Earth's atmosphere over Indonesia, the space agency reported.
Ukrainian President Volodymyr Zelenskyy has awarded US first lady Melania Trump a state honour for her role in helping to organise a humanitarian evacuation from a frontline town last week, according to a decree published on Wednesday.
President Donald Trump acknowledged that the war in Iran played a role in Republicans' losses in Tuesday's midterm elections, as Democrats prepared to take control of both the US House and Senate and challenge his legislative agenda.