Secretary of State Colin Powell told North Korea's top diplomat during a meeting Friday he was hopeful international negotiations begun last year could yield "concrete progress" toward nuclear disarmament in the communist state.

In a North Korean statement issued after the meeting, Foreign Minister Paek Nam Sun (search) was reported to have said he shares Powell's goal of a nuclear-free Korean Peninsula. But he rejected a U.S. requirement that his country show a serious commitment to disarmament before it can receive economic benefits from Washington.

Powell and Paek are here for the annual summer meeting of foreign ministers from the Asia-Pacific region. The unannounced, 20-minute U.S.-North Korean encounter was held shortly after 8 a.m. at a local conference center.

Powell and his North Korean colleague had last met in July 2002 in Brunei (search). Since then, American concerns about North Korea's nuclear intentions have sharply escalated. The North renounced a 1994 nuclear freeze and also was discovered by U.S. intelligence to have secretly embarked on a second nuclear weapons program as supplement to one it publicly acknowledges.

The morning meeting occurred a week after the United States presented a detailed proposal for obtaining a verifiable end to the North's nuclear ambitions. It was unveiled at a conference in Beijing, attended by delegates from China, Japan, South Korea and Russia, in addition to the United States and North Korea. It was the third such meeting among the six.

The plan calls for a step-by-step dismantling of North Korea's declared and undeclared nuclear weapons programs. In return, the North would receive aid, with Japanese and South Korean energy assistance provided at a relatively early stage. American assistance would come later.

After the discussion, Powell said a mutual lack of confidence is a difficult problem in the disarmament talks. Speaking to a group of Indonesian young people, he said, "There is a great deal of mistrust between the United States and North Korea."

Powell told reporters later on that the meeting with Paek didn't change much.

"All we did was to reaffirm the positions that both sides took at the six-party talks last week," he said. "There was no negotiation. We wanted to make sure there was clarity of our position and they wanted to make sure there they had clarity in their position."

State Department spokesman Richard Boucher said Powell outlined the U.S. proposals during his meeting with Paek and told him "there was an opportunity for concrete progress."

The North Korean statement offered a mixed picture of the country's complex relationship with the United States.

It said North Korea "will not regard the United States as a permanent enemy" if Washington seeks improved ties. It also reaffirmed that North Korea's goal is to achieve a nuclear-free Korean Peninsula "peacefully through dialogue."

Paek also told Powell, according to the statement, that North Korea is adhering in the six-nation negotiations to the principle of "simultaneous actions" by the two sides.

This condition is essential, Paek said, because there is "no trust" at present between them.

At a Thursday night news conference, Powell rejected the idea of simultaneity, declaring that North Korea must show a credible commitment to disarmament before receiving economic benefits.

As part of an overall settlement, North Korea would receive security guarantees from other participants in the six-party process.

At last week's talks, North Korea offered to freeze its nuclear program in exchange for guarantees of abundant energy supplies to overcome acute shortages. The North Korean statement on Friday alluded to its proposal as "reward for freeze."

There is virtually no chance that the United States will accept a freeze proposal because it contends that the North unilaterally violated a nuclear freeze pledge in 1994 not long after signing it. The pledge was part of an agreement reached with the United States.

Reinforcing American resistance to a freeze is North Korea's rejection of U.S. claims about a second, secret nuclear weapons program.