New talks aimed at persuading North Korea to give up its nuclear programs opened Wednesday in Beijing, and the chief Chinese envoy called for negotiators to start work on the contentious details of how the North will disarm and what it will get in exchange. The last round of talks ended in September with a pledge by the North to give up nuclear development in exchange for economic aid and a security guarantee. But the North raised doubts about its willingness to proceed by demanding a civilian nuclear reactor before it disarms. The Chinese delegate, Wu Dawei, whose government appealed in advance to the participants to be ready to make progress in the slow-moving talks, called on negotiators to be flexible and pragmatic. In an opening statement, Wu called on all sides to "put forward proposals and ideas so that we will be able to work out an implementation plan that is acceptable to all sides at an early date." Reporters were allowed to hear Wu's opening statement but were ushered out of the meeting room at a Chinese government guesthouse before the other delegates spoke. China says it expects this round of talks to last three days and then recess to let diplomats attend an Asian-Pacific economic conference in South Korea in mid-November. The participants are the two Koreas, China, the United States, Japan and Russia.