Envoys to international talks on ending North Korea's nuclear weapons hit a stumbling block Friday when they failed to back a Chinese proposal for initial disarmament, the main US delegate said. US Assistant Secretary of State Christopher Hill said the Chinese draft proposal, put forward after the talks' first day Thursday, was discussed at a meeting of the delegation heads from the six countries involved. "Opinions were expressed around the room, sometimes divergent opinions on the Chinese draft," Hill said. "There are some differences of views among the various delegations." The one-page plan - presented after North Korea agreed in principle to take initial steps to disarm - would grant the communist nation unspecified energy aid for shutting down its main nuclear facilities, South Korea's Yonhap news agency reported. Officials declined to confirm details of the draft. The US and North Korean envoys held a one-on-one meeting on the proposal later Friday at a Beijing hotel away from the main negotiating venue. "We discussed ways to move the talks forward," the North's Kim Kye Gwan told reporters afterward. "We agreed on some issues, but overall there are still some points of confrontation, and we are going to make more efforts to resolve them." Hill said he was "cautiously optimistic, but I don't want to count chickens before they hatch." "There is a realization that the first step that we are looking at is the big first step ... So I think they want to be sure they understand what is expected of them," Hill said. The US diplomat said some negotiators' concerns focused on which elements would be implemented under the current proposal, and which would be put off until future negotiations. He declined to give specifics. Any agreement on an initial set of reciprocal moves to implement a September 2005 accord - in which North Korea pledged to disarm in exchange for aid and security guarantees - would set the stage for the first tangible steps in the often-delayed six-nation process. The 2005 deal, a broad statement of principles that did not outline any concrete steps for dismantling North Korea's nuclear program, was the only agreement since the negotiations began in 2003. At the last session of the arms negotiations, following North Korea's Oct. 9 underground nuclear test, the North refused to even talk about its nuclear programs. Instead, it demanded the US lift financial restrictions targeting alleged North Korean counterfeiting and money laundering. But since then, the US and North Korean nuclear envoys held an unusual one-on-one meeting in Germany last month, when differences were apparently discussed. However, no details of any concessions have been made public. Pyongyang and Washington held separate talks in Beijing late January on the financial issue, but it has yet to be resolved. The six-nation talks - which involve China, Japan, Russia, the US and the two Koreas - began in August 2003, but the North has twice boycotted them for more than a year. The latest disagreement was over a US decision to blacklist a Macau bank where the North held accounts. Washington said the bank was complicit in the regime's alleged counterfeiting and money laundering.