In a tweet Tuesday, U.S. President Donald Trump announced that he had asked U.S. National Security Advisor John Bolton for his resignation, informing him that "his services are no longer needed at the White House."
The U.S. president added that he "disagreed strongly" with many of Bolton's suggestions, as did others, he said, in the administration.
Trump will be naming a new National Security Adviser next week.
The announcement comes after months of rumors that the two clashed on policy, including on how to denuclearize North Korea.
Some of their disagreements were public, with Trump playing down North Korea's short-range ballistic missile tests, while Bolton called them out as violations of UN Security Council resolutions.
Bolton was appointed as Trump's third national security adviser in April last year, and was widely known to have advised Trump to walk out of the second summit with North Korean leader Kim Jong-un in Hanoi back in February, after Pyeongyang offered to dismantle only its main nuclear facility in Yeongbyeon.
North Korea, too, has numerous times, expressed anger and dissatisfaction with Bolton through various statements.
While Bolton's dismissal will not directly change Pyeongyang's attitude, a North Korea expert says it increases the possibility of U.S. changing its "calculations" and going back into talks.
"North Korea hasn't been a really trustworthy partner ever since Hanoi. The North could still test-fire inter-continental ballistic missiles or satellites, something that would go against President Trump's self-congratulatory comments that the recent launches were only short-ranged missiles, so Trump might be feeling a need to prove that his North Korea policy is successful. And so with Bolton, the hardliner on Pyeongyang, gone, there's a chance Trump might ease up in his negotiations with the North."
The gist of the current tug-of-war between the two sides, the expert said, is whether the U.S. will agree to sanctions relief as part of the North's step-by-step denuclearization.
And with U.S. Secretary of State Mike Pompeo not likely to go hard against Trump, the expert said it remains to be seen what decision the U.S. will make.
Lee Ji-won, Arirang News.