South Korea on Tuesday approved plans by a group of forest experts and officials of Hyundai Asan, a South Korean operator of an inter-Korean tour program, to visit North Korea this week to check pine trees which turned yellow at its scenic mountain resort.

Officials from the state-run Korea Forest Research Institute and Hyundai Asan will be allowed to visit the North starting Wednesday for a three-day stay in a bid to look into what went wrong with the pine trees at Mount Kumgang on the North's east coast, according to the Unification Ministry.

"A total of eight representatives from Hyundai Asan and the Korea Forest Research Institute will visit Mount Kumgang for the on-site survey from July 29-31," a Unification Ministry official said.

It is not immediately clear why the pines turned yellow, but a severe drought that hit the North may be blamed for that, said the official.

Sitting on the east coast near the heavily fortified inter-Korean border, Mount Kumgang is famous for its scenic views, including its impressive peaks and thickly grown pine trees.

Hyundai Asan kicked off a joint tour program at Mount Kumgang in 1998, a symbol of inter-Korean reconciliation, attracting some 2 million South Korean visitors until it was put on hold.

Seoul suspended the tour program in 2008, after the shooting death of a South Korean female tourist by a North Korean solider at the resort.

Pyongyang has called for the resumption of the tour program, which once served as one of the few legitimate revenue sources for the cash-strapped country.