A US team left North Korea on Thursday after two days of talks aimed at restarting a stalled nuclear disarmament deal, officials said.
The US embassy said the team, led by State Department official Sung Kim, returned to South Korea Thursday morning and would leave for Washington on Friday.
"There is no scheduled official meeting (with Seoul officials) as of now," spokesman Max Kwak told AFP.
The team, which travelled by land across the heavily fortified border, discussed Pyongyang's promised declaration of its nuclear activities.
Differences over the declaration have for months blocked progress on a six-nation deal to scrap the communist state's nuclear weapons programmes.
Kim could not be reached for comment Thursday. On his arrival in Seoul Monday en route to Pyongyang, he said he hoped for "significant progress."
Kim said his team would also discuss ways to verify the information in any declaration as well as the document itself. "Everything is subject to verification. That is what we need to focus on," he said.
In last year's landmark deal, the United States, South Korea, China, Japan and Russia agreed to grant North Korea energy aid and major diplomatic and security benefits in return for full denuclearisation.
But the talks have been stalled over the declaration, which was promised by the end of 2007. The North said it delivered the documentation last November but the US said it was incomplete.
In particular, Washington said Pyongyang must clear up suspicions about an alleged secret uranium enrichment programme and suspected proliferation. The North denies both activities.
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.
It would detail its admitted plutonium operation, based on the Yongbyon reactor, in the formal declaration to talks host China.
Despite hopes of progress, US intelligence officials in Washington were scheduled to tell lawmakers later Thursday that Pyongyang had shared nuclear technology with Syria.
The US has concluded that the North helped Syria begin construction of a nuclear reactor, and that the aid did not stop when the site was destroyed, said one official speaking on condition of anonymity.
Israeli aircraft last September attacked a mystery target widely reported to have been a fledgling nuclear site.
The New York Times and The Washington Post said a video showing North Koreans inside the Syrian reactor, which appears identical in design to one at Yongbyon, would also be shown to lawmakers.