North and South Korea held talks on Tuesday about a potential volcanic threat from the peninsula's highest mountain, in a rare interlude of cooperation after months of confrontation.
The meeting at the South Korean border town of Munsan follows heightened concern about natural disasters, after an earthquake and tsunami devastated northeastern Japan and crippled an atomic power plant there.
The North's chief delegate Yun Yong-Gun expressed concern at radioactive leakage from the Japanese plant after his team including three experts crossed the border early Tuesday.
"We are actively watching for fear that radioactive contamination may reach us," he said at the beginning of the talks with four South Korean delegates, according to Yonhap news agency.
After day-long discussions the two sides agreed on the need for joint research into potential hazards from Mount Paekdu on the border between North Korea and China, said Ryu In-Chang, a geologist with South Korea's Kyungbook National University.
The North offered access to the peak for the South's experts, Ryu told reporters, adding that a date for their next meeting would be fixed later.
Pyongyang's official news agency said the two sides "agreed to positively cooperate with each other" and meet again early next month.
Following the Japanese disaster, Pyongyang's earthquake bureau had proposed joint research into possible activity at the mountain, which is considered sacred by both sides.
Mount Paekdu is mentioned in the South's national anthem, while North Korea says its current leader Kim Jong-Il was born there. North Korean schoolchildren are required to visit the peak to pay respects to the ruling dynasty.
Since its last eruption in 1903, the 2,740-metre (9,042-foot) mountain has been dormant. But experts say it may have an active core, citing topographical signs and satellite images.
The South's National Institute of Environmental Research said in a recent report that an eruption could lower temperatures by two degrees Celsius (3.6 degrees Fahrenheit) in northeast Asia for two months, devastating agriculture.
Geologist Yoon Sung-Hyo of Pusan National University told Yonhap last week that a massive release of sulphuric gas was detected from the mountain last November.
Yoon said it was almost impossible to predict when the volcano might erupt, but the South could provide monitoring equipment if the North allowed access.
The talks could also have a political impact, according to professor Kim Yong-Hyun of Seoul's Dongguk University.
Cross-border relations have been icy since the South accused the North of torpedoing a warship in March 2010 with the loss of 46 lives. Pyongyang denies the charge, but went on to shell a South Korean island last November, killing four people.
Kim said the North was putting out feelers for possible dialogue with Seoul. "The meeting is between experts but it could serve as a breakthrough in the frozen ties between the two Koreas," he told AFP.
Concerns about the stability of Mount Paekdu increased after a magnitude-7.3 earthquake hit northeastern China in 2002. Some experts say the North's underground nuclear tests in 2006 and 2009 may also have destabilised its core.
In the event of an eruption, a huge crater lake could overflow and deluge surrounding areas, in addition to other potentially massive damage.
Explore further: Trade winds ventilate the tropical oceans