By Alex Jensen

SEOUL

South Korea’s abandonment from the last tangible symbol of cooperation with North Korea was underway Thursday, a day after Seoul announced it would at least temporarily suspend operations at the Kaesong Industrial Complex.

The facility just north of the inter-Korean border was the product of relatively strong bilateral ties in the early 2000s – at last count, 124 businesses from the South were employing nearly 55,000 local workers in Kaesong.

Having warned that that the suspension would remain in effect while Pyongyang continues to develop nuclear weapons, Seoul was aiming to ensure a safe retreat.

“South Koreans staying there were able to smoothly enter and exit the complex Thursday morning,” a Unification Ministry official was quoted as saying by local news agency Yonhap. “The government is seeking to withdraw South Koreans from there as soon as possible.”

Citizens from either side require permission to cross a border that is particularly tense as the 1950-53 Korean War ended in a truce rather than a peace treaty.

A potential sticking point could be the retrieval of South Korean equipment and products -- a discussion will be required with the North, which has not immediately reacted to Seoul’s move.

The Kaesong closure is likely to be the first of several significant measures aimed at cutting North Korea’s ability to fund its nuclear development.

While on a trip to the United States, South Korean Foreign Minister Yun Byung-se called on the United Nations Security Council Wednesday to break the pattern of resolutions followed by further North Korean provocations.

As Pyongyang has repeatedly ignored UN resolutions with nuclear tests and ballistic missile launches, Yun told reporters that “very large prices should be paid for habitual violations of Security Council resolutions”.

Seoul’s Foreign Ministry also said that Yun asked for a “resolution beyond the North's prediction”.

Meanwhile, military leaders from South Korea, the U.S. and Japan agreed during joint talks Thursday to “react resolutely” through cooperation, according to the South’s Joint Chiefs of Staff.

The U.S. is reportedly set to dispatch a Navy attack submarine to the Korean Peninsula next week, in a similar show of force to that which Washington demonstrated with a B-52 bomber fly-by after January’s nuclear test in North Korea.