United Nations Secretary-General Ban Ki-moon talks during a news conference as he attends a meeting about climate change and sustainable development at the Vatican April 28, 2015. REUTERS/Tony Gentile

By Tony Munroe

SEOUL (Reuters) - U.N. Secretary-General Ban Ki-moon said on Tuesday he will visit the Kaesong industrial complex just north of the inter-Korean border, which will make him the first U.N. chief to enter the isolated country in more than two decades.

The Kaesong industrial complex, a special economic zone a few kilometres north of the heavily fortified border, is jointly run by North and South Korea.

"All parties would benefit from renewed engagement and commitment to genuine dialogue. It is essential for building trust and promoting inter-Korean relations," Ban said at an education forum in the South Korean city of Incheon, adding he aimed to make the visit on Thursday.

"The Kaesong project is a win-win model for both Koreas," he said.

"I hope my visit will provide a positive impetus to further develop it and expand to other areas," he said.

North Korea is under U.N. sanctions for its nuclear and missile programmes.

In December, the U.N. General Assembly urged the Security Council to consider referring North Korea to the International Criminal Court after a U.N. inquiry detailed wide-ranging abuses in the isolated country comparable to Nazi-era atrocities.

Ban was South Korea's foreign minister during six-party talks that led to the signing of a 2005 denuclearisation deal with North Korean, which later fell apart.

He will be the third serving U.N. chief to visit the North, and the first since Boutros Boutros-Ghali crossed through the demilitarized zone (DMZ) between the two Koreas, at Panmunjom, in December 1993.

Kurt Waldheim visited the North Korean capital of Pyongyang in 1979 and again in 1981.

Ban, 70, was born before the Korean peninsula was left divided by the 1950-53 Korean War, which ended in an armed truce, not a peace treaty.

He has previously said he would like to visit the North as U.N. chief under the right conditions, and reiterated a hope earlier on Tuesday to visit the country's capital.

"I have consistently expressed my readiness to visit Pyongyang when and if my visit is helpful," he said at an event in the South Korean capital, Seoul.

The Kaesong complex accounts for nearly all of the bilateral trade between North and South Korea, which totalled about $2.3 billion last year.

The complex generates much-needed income for the impoverished North and is a cheap source of workers for labour-intensive South Korean firms. The two sides are in dispute over wages paid by South Korean companies to the North Korean workers.

(Additional reporting by Ju-min Park; Editing by Robert Birsel)