The head of South Korea's ruling party crossed the border into North Korea Friday to pay a one-day visit to a jointly run industrial complex.

Grand National Party chief Hong Joon-pyo told reporters before leaving for the facility in Kaesong that it is a politician's obligation to try to improve relations.

The complex just north of the border has several South Korean factories that employ cheap North Korean labor.

Hong announced earlier this month that he would be willing to visit the complex in a bid to improve relations between Seoul and Pyongyang.

The two Koreas are slowly attempting to improve ties that turned icy after the North's shelling of a South Korea island last November, and the sinking of a South Korean warship that Seoul blamed on Pyongyang.

Nuclear negotiators for the two countries held talks last week in Beijing, marking their second meeting in two months. The South has also begun allowing a small number of cultural and religious visits to the North.