North Korea's top leader Kim Jong-Il has described the communist regime as "invulnerable," state media said Sunday, as tensions mounted over a planned rocket launch.
Kim made the remark as he watched one of his artillery units perform a live-fire exercise, the Korean Central News Agency (KCNA) said. It did not give a date or location for when Kim made the comments.
"Our socialist fortress is invulnerable and our revolutionary cause is sure to win one victory after another as we have these steel-like elite ranks," Kim said, according to KCNA.
The communist state last week notified international aviation and maritime agencies that it would launch a communications satellite between April 4-8.
Seoul and Washington say the launch is a pretext to test its Taepodong-2 missile -- the first one technically capable of reaching North America. It would be the third long-range missile test since 1998.
The North on Monday switched off military phone and fax lines, used to approve border crossings, and put its 1.2 million-member army on combat alert to protest an ongoing annual US-South Korean military exercise.
It says the exercise involving tens of thousands of troops is aimed at launching a "second Korean War," while Seoul and its ally Washington insist it is a routine annual defensive drill.
The border with the South remained shut for a third consecutive day Sunday, stranding hundreds of South Koreans in the North.
South Korean Unification Minister Hyun In-Taek urged Pyongyang to allow businessmen and investors to travel freely to and from the Seoul-funded industrial site in Kaesong, just north of the border.
"North Korea has repeatedly obstructed the passages of our people, while giving no explanations," Hyun said Sunday at a meeting with southern businessmen.
"North Korea's unilateral and unfair action like this not only undermines inter-Korean accords but also violates its own regulations."
After shutting its usual communication channels on Monday, the North reopened the frontier Tuesday but kept the lines switched off, requiring the exchange of hand-delivered letters to approve crossings.
It again on Friday stopped work on approving border crossings.
Seoul's unification ministry has reported that 427 people were not allowed to return home from Kaesong on Friday and Saturday, with 727 South Koreans staying in the industrial site.