The United States would be happy to meet with North Korea "anytime, anywhere" if the communist nation is ready to talk about giving up its nuclear program, Washington's chief envoy for the nuclear issue said Tuesday.

Amb. Sung Kim, special representative for North Korea policy, said, however, during a Wilson Center discussion that the U.S. has seen no signs of willingness to hold such meaningful negotiations that would lead to concrete, irreversible denuclearization steps.

"I think for us it's pretty straightforward: If they're willing to talk about the nuclear issue and how we can move towards meaningful productive credible negotiations, (we would be) happy to meet with them anytime, anywhere," Kim said.

Kim also said the U.S. offer to hold so-called exploratory talks with the North is still valid.

"The idea that we would be willing to sit down with the North Koreans to test their commitment, test, reaffirm their commitment to denuclearization, I think, is still valid. Unfortunately, the North Koreans have shown no interest in such dialogue," he said.

"We have no qualms about sitting down with the North Koreans to talk about denuclearization and how we can work together ... toward some meaningful negotiations that result in concrete, irreversible denuclearization steps. So I think that idea is still valid, but it's up to the North Koreans and so far they've shown no interest," he said.

The term "exploratory talks" refers to a compromise form of negotiations aimed at meeting both Pyongyang's demand for an unconditional resumption of six-party negotiations and the U.S.

insistence that any formal negotiations should begin only after Pyongyang takes concrete steps toward denuclearization.

Six-party talks have been stalled since the last meeting in late 2008.

Earlier in the day, former New Mexico Governor Bill Richardson suggested the idea of expanding the six-party talks to include more countries, such as Norway.

But Kim said it is "irrelevant" to talk about the format when Pyongyang has shown no interest in talks. He also said that there is value in maintaining the six-party format in that it was in the talks that a 2005 denuclearization deal was reached.

Kim also reiterated U.S. rejection of the North's proposal to hold talks on a peace treaty.

"It's not that we have no interest in seeking a permanent peace regime, peace mechanism or peace treaty. But I think they have the order wrong. Before we can get to a peace mechanism to replace the armistice, I think we need to make significant progress on the central issue of denuclearization," he said.

Kim, who doubles as deputy assistant secretary for Korea and Japan, said the recent summit between South Korean President Park Geun-hye and Prime Minister Shinzo Abe was "very productive" and "very positive."

"It was important for the two leaders to meet and have in-depth discussions on some of the concerns they have and by all accounts, according to briefings we received both in Tokyo and Seoul, the meeting really was very productive," he said.

Kim said the Seoul-Tokyo ties are "a matter of great importance" that directly affect U.S. interests.

With regard to President Barack Obama's calls for South Korea to "speak out" when China violates international norms, Kim said he believes "Korean authorities have made clear their concerns about some of the developments that we're seeing in the region."

He was apparently referring to the South Korean defense and foreign ministers called for freedom of navigation during recent international conferences, a move that was seen as increasing pressure on China over the territorial disputes in the South China Sea. (Yonhap)