South Korean officials say they are reviewing a North Korean proposal for talks on a joint industrial complex, in Pyongyang's first official contact with Seoul in more than a year.

Unification Ministry spokesman Kim Ho-Nyoun said Saturday that North Korea proposed a meeting in the Kaesong industrial zone, without specifying what the talks would be about.  South Korean officials have repeatedly called for access to a South Korean who has was detained at the complex last month for allegedly criticizing North Korea.

Meanwhile, North Korean officials on Saturday reiterated an earlier warning to South Korea against joining the U.S.-led Proliferation Security Initiative (PSI), aimed at stopping the spread of weapons of mass destruction

North Korea's official news service published a statement from an official, spokesman for the  General Staff of the Korean People's Army, saying such a move by South Korea would be considered a declaration of war.

South Korea has delayed its decision to join the initiative amid rising tension with North Korea.

The Kaesong industrial park opened in 2005 and is the last remaining reconciliatory venture between the two Koreas. But North Korea cut official contact with the South and restricted border crossings when President Lee Myung-bak took office last February with a tougher stance on the North.

Relations between the two sides grew tenser after North Korea launched a rocket on April fifth.  North Korea said it was a satellite but others allege it was a test of a long-range ballistic missile.

North Korea announced Tuesday it would halt six-nation disarmament talks and restart its nuclear program in retaliation for a U.N. Security Council statement condemning the launch.

Some information for this report was provided by AFP, AP and Reuters.