With the nuclear dispute with North Korea at an apparent impasse, mr. Bush and South Korean President Roh Moo-hyun put the communist regime on notice that it would not be allowed to keep its nuclear weapons programs.
"A nuclear-armed North Korea will not be tolerated," Roh said through a translator.
Mr. Bush and Roh met ahead of a 21-member trade and economic summit whose members include the leaders of the five countries — the United States, China, South Korea, Russia and Japan — negotiating with North Korea for its nuclear disarmament.
Roh called his fifth meeting with Mr. Bush "constructive."
Roh said the second phase of the fifth round of six-party talks should be held as soon as possible in order to find a breakthrough in resolving the conflict.
Negotiations between North Korea and the United States, Japan, South Korea, Russia and China in September concluded with Pyongyang's promising to end its nuclear program in exchange for aid, diplomatic recognition and security guarantees. But a disappointing new round of talks ended last week without progress on the difficult next step — how to dismantle existing weapons and verify that the country has really ended all suspicious programs.
"The challenge for U.S. and South Korean negotiators will be to determine what are the legitimate interests of Pyongyang and what is a stall," said CBS News foreign affairs analyst Pamela Falk, "The stakes become higher with the passage of time and the development of the uranium enrichment program in North Korea."
Roh, who has pursued engagement and closer ties with the North, opposes military action if diplomacy fails and is cool to going to the U.N. Security Council for sanctions. Mr. Bush has not taken either option off the table.
But, declared Roh: "We have no disagreement at all that this issue must be resolved."
CBS News senior White House correspondent John Roberts reports that even though North Korea has pledged to dismantle its nuclear weapons program, Mr. Bush is skeptical. The White House says the country reneged on a similar deal to shut down their nuclear program in 1994.
South Korea has resisted the tough approach advocated by the Bush administration for ending the impasse with North Korea, opposing the idea of military action if diplomacy fails. South Korea also is cool to the idea of taking the standoff to the U.N. Security Council for possible sanctions.
"The tone is different sometimes because, of course, for the people of the Republic of Korea, the demilitarized zone is right at their doorstep," said Mike Green, senior director for Asian affairs on the National Security Council.
Green said Seoul, the South Korean capital, is as close to the demilitarized zone separating the two countries and to North Korean artillery as the White House is to Dulles International Airport, some 30 miles outside Washington.
"It's very much a clear and present threat for the people," he said.
Many also don't like the U.S. military, which has had a presence in South Korea since the end of the Korean civil war in the mid-1950's. A series of protests are expected over the next two days while APEC leaders meet.
Green, talking with reporters on Air Force One as it flew to South Korea, said Mr. Bush and Roh would discuss ways to strengthen coordination on foreign policy. The objective was to have the pursuit of North-South reconciliation reinforce the disarmament talks, Green said. One proposal calls for a peace treaty to replace the armistice that halted the 1950-53 Korean War.