South Korea is set to discuss North Korea's long-running demand for light-water nuclear reactors if the North makes good on denuclearization pledges, a Seoul official said Sunday.

"If North Korea makes good progress on denuclearization, we can discuss the (light-water nuclear reactor) issue as the next step," the government official said on condition of anonymity, citing a joint statement adopted at six-party talks on Sept. 19, 2005.

The six-way talks include the two Koreas, the United States, China, Japan and Russia.

Under the 2005 statement, the parties agreed to discuss helping North Korea construct a light-water nuclear reactor if Pyongyang gets rid of its nuclear weapons programs.

"But we demand the North return to the frames of the Non-Proliferation Treaty and the International Atomic Energy Agency (IAEA) and comply with all international regulations. Then we will discuss the issue," the official said. "So this is not an issue being discussed yet."

The remarks suggest the six nations will talk about the reactor issue at future multilateral talks as a way to give economic aid to the North in exchange for its denuclearization.

During years of nuclear negotiations, North Korea has demanded the provision of light-water reactors to make up for what it claims are expected electricity shortfalls if it gives up its existing nuclear programs. The North has long maintained the programs are for power generation.

A light-water reactor uses low-enriched uranium as fuel. Highly enriched uranium can be used to build atomic bombs and North Korea has claimed in recent years it has a uranium enrichment program, fueling international concerns about its nuclear capabilities.

South Korea's chief nuclear envoy, Lim Sung-nam, is scheduled to visit New York later this week for an academic forum sponsored by the Maxwell School of Syracuse University, and to meet with his North Korean counterpart Ri Yong-ho.

Lim will ask the North to fully comply with an agreement reached by North Korea and the United States in high-level talks held in Beijing late last month, according to the official.

Under the agreement, Pyongyang agreed to freeze its uranium enrichment program and suspend nuclear and long-range missile tests in exchange for 240,000 tons of food aid from the U.S.

The North also agreed to allow the return of monitors from the IAEA to its main nuclear complex in Yongbyon.

North Korea quit the disarmament-for-aid talks in April 2009 and conducted a second nuclear test a month later. (Yonhap News)