"The talks have ended," a spokesman for one of the six delegations told AFP on condition of anonymity.
"All sides have basically agreed to meet once again before holding the third full meeting of the six nations before the end of June."
The low level discussions that began Wednesday were seeking to set the agenda for a third round of vice-ministerial talks agreed to when the delegations from the two Koreas, China, the United States, Japan and Russia last met in February.
Although the talks were basically over, the delegations were expected to have a "courtesy meeting" with a high-level Chinese foreign ministry official Saturday morning before departing, the spokesman said.
A key sticking point is whether North Korea should give up its entire nuclear program, or only the military part.
Washington wants a clear-cut commitment from the North for a "complete, verifiable and irreversible dismantlement" before any compensation can be considered.
Prior to the talks, Pyongyang had reiterated a demand that it be rewarded, politically and economically, for giving up its nuclear program, while the US government had ruled out any immediate pay-off.
The talks ended as Japanese Prime Minister Junichiro Koizumi said he would meet North Korean leader Kim Jong-Il in Pyongyang next week to discuss the abduction of Japanese citizens and the North's nuclear arms ambitions.
He said the May 22 summit with Kim, their second in 20 months, would help break the stalemate in bilateral rapprochement talks stalled by the kidnap issue and nuclear stand-off.
"I cannot make such a decision unless I have determined that my trip to North Korea will lead to some progress," Koizumi told reporters.
He added that Japan had informed the United States, China and South Korea of his planned visit to the Stalinist state.
The row over North Korea's nuclear program has been deadlocked since October 2002, when Washington said the Stalinist state had broken a 1994 nuclear freeze by launching a secret weapons drive.
In a statement issued outside the North Korean embassy in Beijing late Thursday, foreign ministry official Park Myong-kuk expressed frustration at the US hardline stance.
"We had expected the US to talk differently about what kind of reciprocal measures the US and related countries will take if we freeze our nuclear program," said Park, a member of the North's delegation at the working group meeting.
"But the US repeated the same position as at the previous talks that discussions (on compensation) are possible only when we commit ourselves to CVID (complete, verifiable and irreversible dismantlement)."
He called the US demand "the kind of humiliating measure that can only be imposed on a country defeated in a war".
The statement followed warnings by China that "major" differences remain on solving the 19-month-old standoff and underscored remarks by Russia's envoy that chances of a breakthrough soon were remote.
"With respect to this issue, our policy is clear. The US objective remains the complete, verifiable and irreversible dismantlement of North Korea's nuclear program," a US embassy spokeswoman said, citing a statement from Washington.
In Seoul, South Korean Foreign Minister Ban Ki-Moon voiced optimism that a solution could be found, but said Pyongyang must take the lead.
"North Korea should completely dismantle all nuclear programs including those based on plutonium and highly enriched uranium. This will be the way to guarantee its national security and economic prosperity," he told the Asia Society.