North Korea's demand that it be given a light water reactor before dismantling its nuclear weapons program has sparked mixed reactions from the six nations attending the talks.
The White House says the demand is the opposite of the sequence of events agreed to on Monday and suggested Pyongyang needs time to reflect on the deal. Japan called the demand "unacceptable."
China's Foreign Ministry urged all sides to keep their commitments.
North Korea had pledged to give up its nuclear weapons in return for energy aid and security assurances at talks in Beijing. Parties agreed that supplying a light water reactor for civilian use would be discussed later.
But soon after signing the agreement, the North said Washington should not expect Pyongyang to dismantle its weapons before it received light water reactors.
Some information for this report provided by AFP and Reuters.