North Korea has yet to respond to South Korea's demands made at the conclusion of last week's working-level talks to pull out its last remaining workers from a joint industrial zone in the North, including the resumption of communications lines, a Seoul official said Sunday.

Seoul paid Pyongyang US$13 million in worker wages, corporate taxes and utility charges on Friday, when the last seven South Koreans who had negotiated the settlement of accounts returned home Friday, completing a pullout from the zone amid high tensions on the peninsula.

The Ministry of Unification said Seoul had asked the North to reopen both military and Red Cross hotlines that were cut off earlier in the year, and allow South Korean companies to take finished goods and materials out of the industrial park that has remained idle since early April.

"North Korea has not responded to our demands, such as the reopening of the communications lines," the official said, asking not to be named. "The ball is now in North Korea's court."

The communications lines can be used anytime should North Korea have the will to reopen them, he added.

On March 27, North Korea cut a military hotline with South Korea, which was used notify the North of any planned movement of people and vehicles to the Kaesong complex. The military links were initially established in 2003 to prevent accidental clashes between the two sides that could fray relations.

About two weeks earlier, the North disconnected the inter-Korean Red Cross hotline that ran through the truce village of Panmunjom, six days after it stopped using the phone line with the United Nations Command.

Analysts said Seoul's negotiations for unresolved issues could hit a snag if North Korea remains mum on the South's demands.

Kaesong's operations came to a halt in early April as North Korea withdrew all of its 53,000 workers from 123 South Korean factories in the zone. Before the suspension, the South Korean companies produced garments, wristwatches and other labor-intensive goods there.

The industrial zone, which combined cheap North Korean labor with the South's technology and capital, was the result of the historic summit between late South Korean President Kim Dae-jung and his counterpart Kim Jong-il in June 2000.

South and North Korea remain technically in a state of war since the 1950-53 Korean War ended in a truce, not a peace treaty. (Yonhap News)