BEIJING (Kyodo) The environment ministers of China, Japan and South Korea agreed Sunday to continue joint research and cooperation to tackle the region's sandstorms and air pollution, a Japanese government official said.

The agreement was part of a series of issues discussed in two days of talks in Beijing among China's Zhou Shengxian, Japan's Tetsuo Saito and South Korea's Lee Maa Nee at the 11th tripartite talks on the environment.

According to the official, the ministers agreed to prioritize cooperation in monitoring and prevention of sandstorms.

It will include boosting an early warning system that tells the countries when sandstorms occur, the official said.

Springtime sandstorms originate in arid and semiarid areas of northwest China and Mongolia, sometimes blowing as far as Japan.

Degradation of land from overgrazing, deforestation and excessive cultivation has been blamed for making sandstorms more frequent and intense in recent years.

The ministers also agreed to continue to encourage joint research into photochemical oxidants, which cause smog, depending on their density.

Photochemical smog has been a problem in Japan, particularly in southwestern areas and along the Sea of Japan, and some look to cross-border pollution from China as the cause.

The ministers' agreement will be presented to a summit of the countries' leaders to be held in the summer in China, the official said.