SEOUL - President Obama's envoy to North Korea said yesterday that his journey to Pyongyang produced no commitment that the North would return to international talks aimed at ridding it of nuclear weapons.

But Stephen Bosworth, after a three-day visit that was the first high-level contact between the Obama administration and the government of Kim Jong Il, said his conversations had established a "common understanding" of the need for negotiations.

And the North's Foreign Ministry, in its first reaction to the visit from Bosworth, said in a statement today that it and the United States had agreed to work together to "narrow remaining differences."

Bosworth said that "it remains to be seen when and how [North Korea] will return," adding that "this is something that will require further consultations among all six" of the countries involved in Beijing-based nuclear talks: the two Koreas, the U.S., Japan, China, and Russia.

Bosworth traveled to Pyongyang after Kim sent signals through China and other diplomatic channels that his government might be willing to return to the talks it abandoned last spring, after contending that they had become a vehicle for regime change.

A condition of North Korea's return to negotiations, as determined by Chinese officials in meetings this fall in Pyongyang, was direct high-level contact with the Obama administration.

Yet even as Bosworth headed for North Korea, Obama administration officials were cautioning they had received no guarantee that Pyongyang would return to the often-stalled six-party talks.

Expectations, however, had been raised in Seoul and Tokyo that a U.S. special envoy would not press ahead with a highly publicized visit without some assurances of a substantial result.

Bosworth, though, had little of substance to announce during a news conference in Seoul. He said he did not meet, and did not ask to meet, with the North Korean leader.

Kim, 67, was reportedly out of Pyongyang during at least part of Bosworth's visit, busy giving "field guidance" at a stock farm and a tractor plant, state media reported.

Bosworth said, "It is important to point out that these were exploratory talks, not negotiations." Still, he said that he and the North Korean officials he met - the most senior being Vice Foreign Minister Kang Sok Ju and senior nuclear envoy Kim Kye Gwan - had no discussions about future meetings.

Bosworth said that he and the North Korea officials "did reaffirm to each other" the importance of a 2005 joint statement, when the North promised to get rid of its nuclear program in return for political and economic incentives.

The visit punctuates a strange, tension-filled year on the Korean Peninsula. During the spring and summer, the North exploded a nuclear device, tested a long-range intercontinental missile, expelled international weapons inspectors, restarted its plutonium factory, and threatened "all-out war" against South Korea. But in August, it released two detained U.S. journalists to former President Bill Clinton.