South Korea said Saturday it is reviewing a North Korean proposal for talks on a troubled joint industrial complex where the North is holding a South Korean man, amid rising tensions over the North's recent rocket launch and its expulsion of nuclear monitors.

Separately, North's Korea's military repeated a warning for South Korea to stay out of a U.S.-led security initiative aimed at halting the spread of weapons of mass destruction, saying Seoul's full participation would be seen as tantamount to a declaration of war.

South Korean officials have repeatedly called on the North to grant access to the man detained last month in the factory park in the North Korean border city of Kaesong for allegedly denouncing the North's political system. But the North has refused to do so, without providing any specific reason.

Unification Ministry spokesman Kim Ho-nyeon told reporters that North Korea proposed a meeting with South Korean officials at the complex for Tuesday, but that it was not clear exactly what it wanted to discuss. Kim said South Korean officials were reviewing the proposal.

South Korea's Dong-a Ilbo newspaper said the North wanted to discuss the case of the detained man.

The Kaesong complex has been considered a promising example of inter-Korean cooperation, combining South Korean technology and management expertise with cheap North Korean labor. It is also the last remaining major joint project between the rival Koreas, whose relations have been strained since conservative President Lee Myung-bak took office in Seoul last year with a tougher line on the North.

In recent months the North has taken steps to restrict access to the site by tightening border controls, raising concerns among South Korean companies that have invested there about the project's viability.

North Korea also has been holding two female American journalists who allegedly crossed the border from China on March 17 while reporting on North Korean refugees. It has said it will try the journalists — Laura Ling and Euna Lee of former Vice President Al Gore's Current TV media venture — on charges of entering the country illegally and engaging in "hostile acts."

Tension on the Korean peninsula has heightened since North Korea launched a rocket on April 5 despite repeated international warnings. It insists it sent a satellite into space, but regional powers say nothing reached orbit and the launch was actually a test of long-range missile technology.

North Korea reacted angrily to the U.N. Security Council's condemnation of the rocket launch, saying it would restart its nuclear program, expel international monitors and quit six-nation disarmament talks.

U.N. and U.S. monitors left the communist nation this past week. Their pullout leaves the international community with no onsite means to monitor North Korea's nuclear facilities, which can produce weapons-grade plutonium if restarted.

A spokesman for the North Korean military's General Staff said that South Korea fully joining the Proliferation Security Initiative would be regarded "as a declaration of undisguised confrontation and a declaration of a war against" North Korea.

The unidentified spokesman's comments were carried Saturday by the official Korean Central News Agency.

The PSI, which began in 2003, is aimed at deterring states such as North Korea and Iran from trade in missile and nuclear technology.

South Korea, which has been an observer, had planned to officially announce its full participation Sunday, but decided on a delay following the North's proposal of a meeting about the industrial park, a Foreign Ministry official said on condition of anonymity, citing department policy.

The official did not elaborate, but Yonhap news agency quoted unnamed South Korean officials as saying the delay was aimed at reviewing "factors like inter-Korean talks," but did not mean that South Korea would cancel its plan to join the program.