A new round of six-nation talks aimed at ending a standoff over North Korea's nuclear ambitions looks set to resume in Beijing before the end of June.
The six-nation talks will centre on N Korea's nuclear facilities
The US, China, Japan, Russia and both Koreas have already held two rounds of talks but are still far from agreement.
Washington has accused Pyongyang of a secret uranium programme, and insists it dismantle its nuclear facilities.
But a Chinese official is said to have doubts over Washington's claims, and has urged the US not to hold up talks.
"The six nations share an understanding on the date, but we are not at a stage to officially announce it," South Korean Foreign Minister Ban Ki-moon said.
His comments backed up previous reports that talks would start before the end of June.
Mr Ban also said officials from Japan, South
Korea and the US would meet in Washington before the main talks to co-ordinate their proposals.
The various parties still seem a long way from reaching agreement.
According to a New York Times report on Wednesday, China's deputy foreign minister Zhou Wenzhong remains unconvinced by Washington's claim that North Korea has both uranium and plutonium weapons programmes.
"We know nothing about the uranium programme," Mr Zhou told the newspaper. "We don't know whether it exists."
North Korea has acknowledged a plutonium programme but has denied a uranium one.
The six-nations talks are likely to centre on the disagreement between the US and North Korea.
Washington wants North Korea to completely dismantle its nuclear programme, while
Pyongyang says it will only do so in return for aid and security guarantees.
Meanwhile, tensions remain high between North Korea and its southern neighbour.
On Wednesday, the North's military accused the South of "reckless" military provocation along the disputed sea border, just five days after the two sides agreed to take measures aimed at preventing further naval clashes.
South Korea has deployed more ships in the area "under the pretext of tightening control over fishing boats and
inspection," the North's navy said in a statement issued through the official news agency KCNA.