"I think North Korea is revising its position," South Korean Unification Minister Jeong Se-hyun said. "North Korea has shown some positive steps forward."
Jeong cited North Korea's new willingness to consider President Bush's offer of multilateral security assurances in return for dropping its nuclear programs.
Previously, North Korea had demanded a nonaggression treaty with the United States, a demand that Washington has ruled out.
Separately, South Korean Foreign Minister Yoon Young-kwan said he hoped another round of talks on the nuclear crisis will be held in December.
"The date for the second round of six-nation talks has not been set yet. But our government hopes it will happen in the beginning or middle of December," Yoon said in a briefing.
"Since all the related countries have not started discussing the date, it's still too early to say when," Yoon said.
On Tuesday, North Korea's official news agency, KCNA, questioned the sincerity of Mr. Bush's proposal to provide written security assurances.
During his trip to Asia last week, Mr. Bush called North Korean leader Kim Jong Il's government "failed leadership" and said Kim "let his people starve and shrink in size as a result of malnutrition."
"This is an unpardonable and absurd display of Bush's deeply ingrained disapproval of our system," KCNA said in a commentary monitored by South Korean news agency Yonhap.
"We cannot help raising questions not only on the qualifications of Bush as a political leader but also on whether he really intended to resolve the (nuclear) issue when he said he would provide written security assurances," KCNA said.
Any agreement on the nuclear standoff is likely to take many rounds of tough negotiations. A key question is whether secretive North Korea would be willing to grant enough access for inspectors to verify that it has dismantled its nuclear facilities.
Jeong, the chief negotiator in regular, Cabinet-level talks between North and South Korea, said North Korea was also likely to demand economic assistance as part of any deal. He said the North Koreans wanted a deal to be implemented with "simultaneous actions" by both sides.
Representatives of the United States, China, Russia, Japan and the two Koreas met in Beijing in August for talks aimed at ending the nuclear crisis. The meeting ended without agreement on a new round.
Wu Bangguo, China's second-ranking party and government leader after President Hu Jintao, is to pay a three-day visit to North Korea beginning Wednesday. He would be the highest-ranking Chinese visitor to Pyongyang since then-President Jiang Zemin in August 2001.
The nuclear dispute with North Korea erupted a year ago when a U.S. envoy said he was told the North was pursuing uranium refinement, in apparent violation of a 1994 agreement with the United States. The U.S. and allies suspended fuel shipments to the North, which responded by kicking out atomic inspectors and vowing to restart its plutonium enrichment program.
Since then, the North has vowed to test a bomb — a move that would challenges Mr. Bush's pledge that he will "not tolerate" nuclear weapons on the Korean Peninsula.
The CIA thinks Pyongyang already possesses one or two crude nuclear devices, and might have a missile that can reach the western United States.
North Korea has offered several rationales for why it wants a bomb. It says it feels threatened by the Bush administration because the Mr. Bush considers North Korea part of an "axis of evil" and supports preemptive war. Some 39,000 American troops are in South Korea and an additional 42,000 are in Japan; taken together, that is the largest foreign deployment of U.S. troops outside of the Iraq theatre.
Pyongyang has also said it needs nuclear weapons to serve as a deterrent that is cheaper to maintain than its million-man army.
However, many Korea analysts believe the impoverished North merely wants to leverage more aid from the West.
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