The first day of the latest North Korea nuclear talks has ended with some optimism about prospects for resolving the long-standing issue.

Chinese Foreign Ministry Spokesman Qin Gang said all six parties had frank and serious exchanges on the first day of the talks aimed at ending North Korea's weapons programs.

Mr. Qin says China hopes the participants will take a flexible and practical attitude to move forward on the de-nuclearization of the Korean Peninsula on a step-by-step basis.

The meetings ended Pyongyang's 13-month boycott of the negotiations.

In his opening statement the U.S. envoy to the talks, Christopher Hill, said the United States is prepared to take corresponding measures if the North decides to abandon its nuclear weapons programs, based on the principle of words for words, actions for actions.

Pyongyang has maintained in the past that its nuclear weapons development is a deterrent to possible U.S. military action. But North Korean Vice Foreign Minister Kim Kye Gwan said his country is interested in de-nuclearizing the Korean peninsula.

Mr. Kim says real progress will require very firm political will, and a strategic decision of those interested in ending the threat of nuclear war.

Before the talks, diplomats, including the North Koreans, said progress must be achieved in this fourth round of meetings for them to be credible. Three previous rounds since 2003 achieved little on the goal of convincing North Korea to abandon its nuclear weapons programs.

The participants have been holding bilateral discussions on the sidelines of the official talks. U.S. and North Korean delegates met separately for the second time in as many days. Mr. Qin said the participants are expected to hold frequent bilaterals because there are many issues to be resolved.

There is no word on North Korea's response to a South Korean proposal to provide all of the North's electricity needs in exchange for disarmament. The offer appeared to have prompted Pyongyang to agree to the talks.

None of the officials here expect a final settlement, but say they have set no end date for the talks to maximize the chance of progress.