Updated

North Korea said Friday it will work with the United States to resolve unspecified differences remaining after rare high-level talks with President Barack Obama's envoy aimed at restarting international nuclear negotiations.

It was North Korea's first reaction to three days of talks with special envoy Stephen Bosworth, who arrived in Beijing on Friday to brief Chinese officials.

North Korea's Foreign Ministry said it understands the need to resume the six-nation nuclear talks that the communist nation walked away from earlier this year — vowing never to return — before conducting its second-ever nuclear test.

Bosworth said after leaving North Korea on Thursday that the two sides reached a "common understanding" on the need to restart the nuclear negotiations.

In Beijing, Bosworth was to meet Foreign Minister Yang Jiechi and China's nuclear envoy, Vice Foreign Minister Wu Dawei, a ministry spokeswoman said.

Though North Korea stopped short of making a firm commitment to return to the negotiating table, its reaction was positive and raised hopes that the stalled disarmament process could resume.

Its Foreign Ministry said the meetings with the U.S. "deepened the mutual understanding, narrowed their differences and found not a few common points."

The two sides "also reached a series of common understandings of the need to resume the six-party talks and the importance of implementing" a 2005 disarmament pact, it said in a statement carried by the official Korean Central News Agency.

"Both sides agreed to continue to cooperate with each other in the future to narrow down the remaining differences," it said, without elaborating on the remaining differences.

The 2005 pact — negotiated in the on-again-off-again talks involving the two Koreas, China, Japan, the U.S., and Russia — calls for North Korea to end its nuclear programs in exchange for economic aid, security assurances and diplomatic recognition.

In Washington, Secretary of State Hillary Rodham Clinton said for a "preliminary meeting, it was quite positive."

In Oslo, Obama called for international support for getting Iran and North Korea to forgo their nuclear ambitions.

"It is also incumbent upon all of us to insist that nations like Iran and North Korea do not game the system," Obama said in his Nobel Peace Prize acceptance speech.

North Korea walked out of the talks earlier this year in anger over international criticism of its ambitions to develop rocket technology that could be used one day to send a long-range missile hurling across the Pacific.

Weeks later, it conducted a nuclear test, test-fired a series of ballistic missiles and restarted its nuclear facilities. The defiance earned widespread condemnation and tighter U.N. sanctions. North Korea called it an issue between itself and the U.S. and demanded bilateral talks.

Bosworth's trip marked the Obama administration's first high-level talks with North Korea.

He met with First Vice Foreign Minister Kang Sok Ju, leader Kim Jong Il's top foreign policy brain, as well as North Korea's chief nuclear envoy, Vice Foreign Minister Kim Kye Gwan. The visit did not include a meeting with leader Kim.

North Korea said the two sides "had a long exhaustive and candid discussion on wide-ranging issues" including denuclearizing the Korean peninsula, forging a peace treaty, improving bilateral relations and economic and energy assistance.

North Korea has long sought diplomatic relations with the U.S., which fought for South Korea during the 1950-53 Korean War. Washington still has 28,500 troops stationed in South Korea, which technically remains at war with the North because they signed a truce, not a peace treaty, to end the fighting.

North Korea routinely accuses the U.S. of plotting to attack, and says it needs a nuclear arsenal to defend itself. The U.S. denies planning to invade the North.

Analysts said it was too early to call Bosworth's mission a success. Lee Sang-hyun of the Sejong Institute, a private security think tank outside Seoul, predicted a "tug of war" over when North Korea should rejoin the talks.

"North Korea will only return to the talks after the U.S. offers it a face-saving move or substantial rewards," he said.

Meanwhile, the Tokyo-based Choson Sinbo newspaper, considered a mouthpiece for North Korea's government, reported Friday that the North would not rejoin any multilateral nuclear talks without assurances of an end to "hostile relations between North Korea and the U.S."

After visiting Beijing, Bosworth heads for Moscow and Tokyo to brief them on his North Korean visit.