U.N. Secretary-General Ban Ki-moon says he will visit a factory park in North Korea that is the last major cooperation project between the rival Koreas.

Ban told reporters in South Korea on Tuesday that he hopes his Kaesong visit on Thursday would help improve ties between the Koreas.

Ban would be the first U.N. chief to visit the factory park and the first to visit North Korea since his predecessor Boutros Boutros-Ghali travelled there in 1993.

The visit comes as relations between the Koreas remain strained following the North's continuation of missile and other weapons tests.

The park, opened in 2004 at the North's border town of Kaesong, has been considered as a test case for unification as it pairs cheap local labor with South Korean knowhow and technology.