North Korea rejected an invitation for leader Kim Jong Un to attend a planned summit in South Korea next week with Southeast Asian nations, saying it would be "pointless" due to strained ties with Seoul, North Korean state media reported on Thursday.
"He has given North Korea everything they want", he said during the Democrat debate hosted by MSNBC and the Washington Post, adding that President Trump gave the regime "legitimacy by having a meeting with Kim Jong-un, who's a thug".
KCNA said Moon's office sent a letter on November 5 inviting Kim to attend a summit Moon is hosting in the southern city of Busan for Southeast Asian leaders on Monday and Tuesday.
The statement accused South Korea of failing to implement agreements from past summits between Kim and Moon by depending on the United States.
Biegun also dismissed the significance of Kim's "artificial" deadline, and said American negotiators "will be at this as long as it takes". USA officials say they are giving South Korean officials time to reconsider United States demands.
Esper has no direct role in nuclear diplomacy, but he had hoped that his decision to postpone a military flying exercise with South Korea - which North Korea had criticized as provocative -would help nudge the North back to the negotiating table.
Under U.S. law, the United States' troop presence in South Korea must not fall below 22,000 unless the Secretary of Defense justifies a further reduction to Congress.
But there has been no significant progress amid tightening sanctions aimed at the North's nuclear and missile programmes, and lacklustre denuclearisation talks between Pyongyang and Washington. Together they pose risks to USA national security and to the future of Washington's alliance with South Korea.
The two leaders agreed in June, at a third meeting, to reopen negotiations, but working-level talks in October in Sweden, led by Biegun on the US side, ended with the North Korean envoy accusing the Americans of coming to the table empty-handed.
Stating there is a right time and place for everything, the agency said Seoul is greatly mistaken for thinking that it can easily resolve the cross-border situation by sending a piece of paper inviting Kim to the Busan event. Kim and Moon during their Pyongyang meeting visited Mount Paektu, a volcano North Koreans consider sacred, in a gesture of engagement.