SEOUL, South Korea (AP) -- North Korea abruptly withdrew its staff from a liaison office with South Korea on Friday, a development that is likely to put a damper on ties between the countries and further complicate global diplomacy on North Korea's nuclear program.
The North Korean action came a week after its vice foreign minister threatened to pull out of nuclear negotiations with the United States, citing a lack of U.S. steps to match disarmament measures it took last year. Her warning followed a U.S.-North Korea summit in February that collapsed due to disputes over U.S.-led sanctions on the North.
North Korea informed South Korean officials of its decision during a meeting Friday at the liaison office in the North Korean border town of Kaesong, Seoul's Unification Ministry said.
North Korea said it was withdrawing its staff under instructions from unspecified "higher-level authorities," according to a Unification Ministry statement. It didn't say whether the withdrawal would be temporary or permanent.
South Korea called the North's decision regrettable and urged the North to return its staff to the liaison office soon.
The withdrawal is a major setback for South Korean President Moon Jae-in, who has sought improved relations with North Korea alongside the nuclear negotiations between the North and the United States.
Moon's office said presidential national security adviser Chung Eui-yong convened an emergency meeting of the National Security Council to discuss the North Korean withdrawal.
Moon says inter-Korean reconciliation is crucial for achieving progress in nuclear negotiations, but the breakdown of last month's summit between U.S. President Donald Trump and North Korean leader Kim Jong Un has created a difficult environment to push engagement with the North. North Korean state media have recently demanded that South Korea distance itself from the U.S. and resume joint economic projects that have been held back by the U.S.-led sanctions against the North.
Analyst Cheong Seong-Chang at South Korea's Sejong Institute said North Korea may be trying to pressure South Korea to back its position with the United States more strongly. "It's hard to rule out the possibility that the North will soon announce a hard-line statement regarding the denuclearization negotiations," Cheong said.
Last Friday, North Korean Vice Foreign Minister Choe Son Hui said her country has no intention of compromising or continuing the nuclear talks unless the United States takes steps commensurate with those the North has taken, such as its moratorium on missile launches and weapons tests, and changes its "political calculation." She said Kim would soon decide whether to continue the talks and the moratorium.
U.S. Secretary of State Mike Pompeo responded that the U.S. expects Kim to honor his promise to keep missile launches and nuclear tests on hold.
The Unification Ministry statement said North Korea said it "will not mind the South remaining" in the liaison office and that it would notify the South about practical matters later. South Korean Vice Unification Minister Chun Hae-sung told reporters that the South plans to continue to staff the liaison office normally and expects the North will continue to allow the South Koreans to commute to the office.
The office opened last September as part of a flurry of reconciliation steps that also included North Korea's participation in last year's South Korean Winter Olympics, the mutual dismantling of front-line guard posts and the halting of military exercises along their border.
The liaison office is the first since the peninsula was split into a U.S.-backed capitalistic South and a Soviet-supported socialist North in 1945. The Koreas previously used telephone and fax-like communication channels that were often shut down in times of high tension.
Kaesong is also the location of a now-shuttered factory complex that was jointly run by the two Koreas. It combined South Korean capital and technology with cheap North Korean labor. Both Koreas want the U.S. to allow exemptions from the sanctions to permit the reopening of the factory park, which provided North Korea with much-needed foreign currency.
Chun said a number of North Korean officials left the liaison office carrying documents, but most of the equipment was left behind.
While the liaison office was one of the main agreements reached in three summits between Moon and Kim last year, Chun said it's too early to say whether North Korea is renegading on the deals.
"We don't think this could be called a violation of an agreement," Chun said. "We want to monitor the situation for a bit longer and respond to the developments, instead of making predictions or premature judgments."