SEOUL (Kyodo) -- North Korea expressed readiness to hold talks with the United States, South Korea's presidential office said Sunday, in a surprising remark raising hopes for easing tensions between Washington and the nuclear weapons-pursuing Asian country.
During talks with South Korean President Moon Jae In and Pyongyang's high-ranking delegation to the Pyeongchang Winter Olympics, the two Koreas agreed that bilateral relations should be developed, while promoting U.S.-North Korea talks, the office said.
But it is uncertain what kind of talks Pyongyang is preparing for. The United States has reiterated that it will not sit at the same table unless North Korea promises to freeze or abandon its ballistic missile and nuclear weapons development programs.
Pyongyang may be eager to start negotiations with Washington as a nuclear rival, some foreign affairs experts say.
In Sunday's talks, the North Korean side also told the South that its leader Kim Jong Un shares the view with Moon that it is important to improve and expand inter-Korean ties, the presidential office said.
Moon urged Pyongyang to begin talks with Washington to resolve issues surrounding the Korean Peninsula in a fundamental manner, the office said in a brief statement, in which it did not use the word "nuclear."
Earlier in the day, the North's delegation to the closing ceremony of the Olympics, led by Kim Yong Chol, the head of the ruling party's United Front Department, arrived in South Korea, with protesters demonstrating against his visit.
As Kim Yong Chol is believed to have masterminded attacks on a South Korean warship and island in 2010 that killed 50 people in total, criticism has been growing against his visit to South Korea, especially from conservatives.
Meanwhile, Choe Kang Il, an official in charge of negotiations with the United States, has accompanied the delegation, the South's Unification Ministry said, indicating the possibility of Pyongyang and Washington having contact during its stay in South Korea.
Hundreds of people protesting Kim Yong Chol's visit rallied near a road where the North Korean delegation entered Seoul.
The South Korean government is on alert for any attempt to obstruct the delegation's travel and any possible attack on Kim Yong Chol, a former head of North Korea's Reconnaissance General Bureau.
Later the delegation, which is scheduled to remain in the South through Tuesday, arrived in Pyeonchang, east of Seoul, to participate in the closing event of the Olympics.
For the Olympics opening ceremony earlier this month, North Korea also sent a high-level delegation that included leader Kim Jong Un's sister and close aide, Kim Yo Jong, and ceremonial head of state Kim Yong Nam.
In talks with Kim Yo Jong and other officials, Moon was invited to visit Pyongyang for a summit, an extremely rare move as the two nations remain technically at war after the 1950-53 Korean War ended in a cease-fire.
Since the war, the leaders of the two Koreas have held formal talks only twice, in 2000 and 2007.
Kim Yong Chol, a vice chairman of the Central Committee of the Workers' Party of Korea, is blacklisted under unilateral sanctions adopted by both the United States and South Korea. Seoul has temporarily lifted the sanctions to allow him to visit South Korea.
He allegedly orchestrated the sinking of a South Korean warship in the Yellow Sea in March 2010, killing 46 sailors, for which Seoul blamed North Korea. Pyongyang denied involvement.
Moreover, Kim Yong Chol is suspected of leading the artillery attack in November that year on the South's Yeonpyeong Island near the tense western sea border, killing two soldiers and two civilians. It was the first attack on South Korean territory claiming the lives of civilians since the Korean War.
On Sunday, U.S. President Donald Trump's daughter and adviser Ivanka Trump also took part in the closing ceremony.
A senior U.S. official said Ivanka had no interaction with the North's delegation. But some member of the U.S. delegation might have contact behind the scenes, sources close to the matter said. The United States and North Korea have no diplomatic ties.
Relations between the two Koreas have shown signs of improving after Pyongyang decided to join the Pyeongchang Olympics.
The United States and Japan, however, have pledged to continue maximizing pressure on North Korea, as Pyongyang is still vowing to continue its ballistic missile and nuclear development programs.
On Friday, Washington imposed sanctions against 56 vessels, shipping companies and trade businesses linked to North Korea in what Trump called the "heaviest" sanctions ever imposed on the country.
Trump also warned that if the sanctions do not lead North Korea to move toward denuclearization, the United States may have to take a "very rough" step, signaling he does not rule out a military option in dealing with Pyongyang.
The official newspaper of North Korea's ruling party said in an editorial earlier this month that Pyongyang has become a nuclear power thanks to earnest efforts by Kim Jong Il, father of the current leader.
"We have to boost our prestige as the world's strongest nuclear nation," the Rodong Sinmun, North Korea's most influential newspaper, said, suggesting Pyongyang is intending to develop weapons of mass destruction despite a thaw with the South.