North Korea's deputy nuclear envoy said Friday that he held a "useful dialogue" with American scholars in New York but did not give details on the meeting.

"I had a useful dialogue," Ri Gun, who also serves as head of the North American bureau at the North's foreign ministry, was quoted as telling reporters after emerging from a seminar organized by the National Committee on American Foreign Policy and the Korea Society.

Ri said he attended seminars in San Diego and New York and met with Sung Kim, the U.S. special envoy to six-party talks on Pyongyang's nuclear ambitions, "at the U.S. request."

But he was tightlipped about addressing other questions, including whether and when Stephen Bosworth, Washington's special representative for North Korea policy, will visit Pyongyang.

U.S. figures who attended the meeting with Ri said there were some positive, albeit not concrete, signs.

Winston Lord, a former U.S. ambassador to China and assistant Secretary of State for East Asian and Pacific Affairs, said, "The mood was much better than we've seen in months."

He added, however, that he heard no specific initiatives that would lead to breakthroughs during the group sessions.

Evans Revere, president of the Korea Society and a former State Department official, also said, "We have heard and read comments coming from the DPRK (North Korea) side in various ways that suggest that there has been an uptick in North Korean interest in resuming bilateral and even multilateral dialogue,"

Ri and Sung Kim held one-hour talks in New York last weekend, where they apparently discussed conditions for Bosworth's trip to the North. Their meeting was the first government-level talks between the two sides since President Barack Obama took office early this year.

The results of the Ri-Kim meeting remain a secret, but major Japanese daily Yomiuri Shimbun reported that the two reached a "basic agreement" on Bosworth's visit to Pyongyang in late November.