U.S. Secretary of State Mike Pompeo will not step down from his role in the negotiations with North Korea, despite calls from Pyonyang for him to step aside and let someone "more mature" take over.

"Nothing's changed. We're continuing to work to negotiate. I'm still in charge of the team," Pompeo said in Washington, at a press conference with visiting Japanese ministers.

Pompeo also insisted he was not misrepresenting the North Korean side and that Kim Jong Un, the leader of the reclusive Asian state, had promised to denuclearize.

Japanese Foreign Minister Taro Kono said his country was "ready to normalize the relationship with North Korea when this missile, nuclear, and abduction issues are taken care of," in remarks said through a translator.

In addition to the increasing hostility towards Pompeo personally, North Korea this week tested a "new type of tactical guided weapon," its state news agency reported, the country's first known weapons test since February's failed US-North Korea summit in Hanoi.

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