Busan, South Korea ? Thousands of South Koreans staged a pro-U.S. rally Sunday and prayed for North Korea to give up its nuclear ambitions, while an envoy of South Korea’s president-elect urged Washington to hold direct talks with the communist nation.

Returning from a visit to Washington and Tokyo, President-elect Roh Moo-hyun’s envoy said he had made the case for dialogue.

“I asked Washington to open direct U.S.-North Korea talks soon without condition,” Chyung Dai-chul told Korean reporters, according to his aide Park Jin-hyung. Roh takes office Feb. 25.

President Bush believes the standoff can be resolved peacefully, but said Friday that “all options are on the table,” suggesting that Washington would consider military action.

Relations between the United States and North Korea deteriorated in October, when U.S. officials said North Korea had admitted developing nuclear weapons in violation of a 1994 agreement. The United States retaliated by canceling fuel oil shipments.

U.N. nuclear chief Mohamed ElBaradei on Sunday cautioned North Korea about indulging in “nuclear blackmail.”

ElBaradei acknowledged North Korean humanitarian and security needs but said those issues “should be resolved quite independently.”

“The lesson would be very dangerous if it shows that nuclear blackmail pays,” ElBaradei told The Associated Press. “That, I think, is a very dangerous precedent.”

Also Sunday, about 3,000 people attended a pro-U.S. rally in South Korea’s second-largest city, Busan. The demonstrators burned a picture of North Korean leader Kim Jong Il, waved American flags and prayed for an end to North Korea’s nuclear ambitions.

But there is little sign of an end to the standoff after the North suggested it reactivated nuclear facilities that U.S. officials say could produce weapons within months.

North Korea accuses the United States of inciting nuclear tension as a pretext to invade the communist county, and has warned of a “total war” that could devastate both Koreas.

Secretary of Defense Donald Rumsfeld said that most intelligence services know the North Koreans have “one or two nuclear weapons,” and that by May or June “they may have enough nuclear material to make an additional six to eight nuclear weapons.”

ElBaradei said there was no proof North Korea had a nuclear weapons program, but he pointed out that it was known to have plutonium.