The multilateral talks have been stalled for months by a dispute over the North's declaration on its nuclear weapons program and proliferation activities, which they promised to provide by the end of 2007 as part of the aid-for-disarmament deal.
"They did, as I understand it, have a chance to meet with Kim Gye Gwan today and they'll be continuing their discussions over the next day or so," State Department spokesman Tom Casey said, referring to the team of US experts.
"Their focus ... is to work on the declaration," he said.
Kim has been leading the North Korean delegation to the six-party talks launched in 2003 among the United States, China, the two Koreas, Japan and Russia aimed at ending North Korea's nuclear weapons drive.
Washington says Pyongyang should not only account for its plutonium program but also clear up suspicions about an alleged uranium enrichment program and suspected proliferation -- claims denied by North Korea.
According to numerous reports, the North in a face-saving gesture will merely "acknowledge" US concerns about the two issues in a confidential document to the United States.
Casey said he hoped the latest meeting with the North Koreans "will make progress toward getting that declaration.
"But I'm really not in a position to try and handicap for you exactly how close or how far away we are at this point," he added. "This really is an issue where it's not done until everything is done."