South Korea's chief nuclear negotiator is in Beijing for the latest round of talks on efforts to restart negotiations on North Korea's nuclear programs.

The visit comes as South Korean President Lee Myung-bak flies to Moscow for talks expected to deal with the nuclear issue as well as a proposed trans-Korea gas pipeline.

Nuclear envoy Lim Sung-nam told reporters in Beijing Tuesday he expects to brief his counterparts on a series of recent diplomatic contacts, including last week's direct talks between North Korea and the United States.

He said he would also discuss the next steps in the effort to re-start six-nation nuclear talks involving the two Koreas, China, the United States, Japan and Russia.

Mr. Lee's office said the nuclear negotiations would also figure in the South Korean president's talks Wednesday with Russian President Dmitry Medvedev.

A breakthrough on the nuclear issue would help to clear the way for a proposed pipeline to carry Russian natural gas across North Korea to Seoul. North Korean leader Kim Jong Il has endorsed the plan, but South Korea will need assurances that gas supplies will not be disrupted by Pyongyang.

Diplomacy aimed at re-starting the six-party talks has escalated since July, with North Korean negotiators meeting twice each with South Korea and the United States.

U.S. officials emerged from the latest round of meetings with North Korea saying that, with goodwill on both sides, it should be possible to find terms to restart the negotiations.

Pyongyang seeks an unconditional resumption of the negotiations, which would give it financial and diplomatic benefits in exchange for dismantling its nuclear weapons programs. The United States and South Korea say the North must first shut down a newly disclosed uranium enrichment program and honor other commitments made in previous talks.