President Bush said Sunday he believes there is a "good chance" of persuading North Korea to end its nuclear weapons programs.

He said the United States was working with China, Japan and South Korea toward a goal of a nuclear-free Korean Peninsula. A multilateral approach to the crisis — rather than the direct U.S.-North Korea engagement that Pyongang had been demanding — has been key to the U.S. strategy.

"I believe that all four of us working together have a good chance of convincing North Korea to abandon her ambitions to develop nuclear arsenals," Bush told reporters after meeting at an Army base with two helicopters pilots who were held as prisoners of war in Iraq.

Plans for U.S.-North Korean talks, possibly this week in China, on the North's nuclear weapons program were thrown into uncertainty Friday after the communist state appeared to announce steps that could yield six to eight bombs within months.

The confusion about North Korea's intentions came days after the State Department disclosed plans for talks involving the United States, North Korea and China.

Bush seemed to lay to rest questions about whether those talks would proceed. He was responding to a question about whether the talks would go on and whether he expected a breakthrough.

"The key thing on the North Korea agenda is that China is assuming a very important responsibility," Bush said. "Now that they're engaged in the process, it makes it more likely" that the countries' policy of a nuclear-free Koreas will result.

Bush's optimism contrasted with another angry pronouncement Sunday from North Korea, which said South Korea should join it in resisting U.S. moves toward war.

North Korea repeatedly has accused the United States of planning to attack it after the Iraq war, a charge denied by Washington. The North's intention in making the statement was not clear, but it has often tried to drive a wedge between South Korea and its chief ally, the United States.

The talks would be the first opportunity for substantive discussions with North Korea since October, when U.S. officials said the North admitted having a uranium-based nuclear program.

The United States believes North Korea already has one or two nuclear bombs and can extract enough plutonium from the fuel rods to make several more within months.

North Korea has never admitted or denied having nuclear bombs, but has said it has the right to develop such weapons.

Earlier Sunday, the chairman of the Senate Intelligence Committee said he thought the meeting would go ahead.

"China's the key here, and China has made some significant changes here just recently in their attitude to North Korea," Sen. Pat Roberts, R-Kan., told Fox News Sunday.

Asked if North Korea was the major security threat facing the United States, Roberts said: "Without question. I would probably name it number one right now."