President Roh Moo-hyun (searchsaid Monday that South Korea and the United States would never tolerate North Korea's possession of nuclear weapons, and they would strive to resolve the ongoing nuclear tension peacefully.

"South Korea and the United States share a firm principle that North Korea should never possess nuclear weapons and that the issue should be resolved through a peaceful manner," Roh said in a nationally televised news conference.

Roh, who will mark his 100th day in office on Wednesday, held the news conference after meeting with U.S. Deputy Defense Secretary Paul Wolfowitz (search), who arrived in Seoul on Sunday for a two-day visit.

The United States and its allies are calling for international pressure to be put on North Korea to give up its nuclear ambitions.

U.S. officials have said North Korea (searchclaimed at talks in April in Beijing that it already had nuclear weapons, but would give up its nuclear programs in return for economic aid and security guarantees.

Roh said South Korea could not verify the claims.

But when Roh and Japanese Prime Minister Junichiro Koizumi met with President Bush in Washington last month, the leaders vowed to take "further steps" or "tougher measures" against North Korea if the nuclear tension escalated.

Asked what tough action could be taken, Roh said, "Our firm emphasis is on peace."

"As part of negotiations, those involved talked about both tough and soft measures. We should not react too sensitively," he said.

The nuclear crisis flared last October when U.S. officials said North Korea admitted running a secret nuclear weapons program in violation of a 1994 accord with Washington.