Negotiators wrapping up this week's session of talks aimed at ending North Korea's nuclear weapons programs are defending their decision not to set deadlines for future action at this time. As VOA's Kurt Achin reports from Beijing, diplomats are handing over some of the thorniest technical issues to experts for several months before deciding how to proceed.

As he prepared to board a plane for Washington at Beijing's airport, U.S. Assistant Secretary of State Christopher Hill gave a glowing review of this week's six-nation talks.

"We came through I think what is arguably the most productive week in the six party process," he said.

Hill is Washington's chief envoy in charge of seeking a diplomatic end to North Korea's nuclear weapons capabilities. He met this week with counterparts from China, Japan, Russia, and North and South Korea.

Hill praised the shutdown of North Korea's main nuclear facility at Yongbyon in keeping with a February agreement, and said the six nations fine-tuned their "vision" for the next phase of talks. This requires North Korea to declare all of its nuclear programs, as a prelude to disabling them in exchange for energy aid and diplomatic benefits.

What this week's talks did not do, was set any specific deadlines for future actions. South Korea's delegate, Chun Yung-woo, says that should come as no surprise.

Chun says the six parties basically knew coming in to the talks that they would not reach specific agreements during this session, because the issues at hand are so complex.

According to a statement Friday from China's Foreign Ministry, which chaired the talks, the six nations will hand over the more daunting technical issues to expert "working groups." The experts will have until late August or early September to draw up a menu of options for pushing the February agreement forward.

Ambassador Hill says it is only then that the six nation diplomats will reconvene and start considering timetables. Overall, Hill says he hopes North Korea's nuclear programs can be dismantled within about a year and a half.

"I would like as a sort of target time frame to get through the end of '07 and then get on to what I believe is the end game in '08," he said. "And I think it's feasible, but I'll know better when I see the working groups."

Hill says steady progress is more important, however, than adherence to exact deadlines.

"You know, it is not so important whether it is done in November, or February," he said. "What is important is that we continue to make perceptible progress toward our goal, which is complete denuclearization of the Korean peninsula."

Hill says the six nations remain intent on scheduling a ministerial version of the six party talks, attended by Secretary of State Condoleezza Rice and her counterparts, before the end of the year.