Japan, China and South Korea agreed Monday to cooperate in the fight against cross-border air pollution, despite strained relations between the neighbours because of territorial disputes.

The annual ministerial environmental meeting in Kitakyushu, southern Japan, on Sunday and Monday, came after acrid haze blanketing swathes of China earlier this year sparked health warnings in Japan as the smog spread across the ocean.

The meeting agreed the launch of a new forum to share information on environmental policy and technology, according to a joint statement.

"We have made a new step toward solving the air pollution problem through cooperation among Japan, China and South Korea," Japan's Environment Minister Nobuteru Ishihara told a news conference.

Ishihara earlier told his counterparts in remarks carried by public broadcaster NHK that it was "indispensable for China, South Korea and other countries to cooperate" on issues such as air pollution and climate change.

Zhou Shengxian, China's minister for environmental protection, cancelled his attendance, citing a tight schedule after the earthquake in Sichuan last month.

But Japanese media reported the likely influence of a territorial dispute over the Japanese-controlled Senkaku islands in the East China Sea, which Beijing also claims and calls the Diaoyus.

Li Ganjie, China's vice minister for environmental protection, who attended in his place, was shown on NHK saying: "We wish to create a more beautiful environment in Asia by continuing cooperation with Japan and South Korea."

South Korea's Environment Minister Yoon Seong-Kyu told the meeting that the three-way cooperation on environmental issues had reached a "new turning point" with new governments in all three countries.

Relations between Tokyo and South Korea have been strained by a separate territorial row over a Seoul-controlled chain of islets in the Sea of Japan (East Sea).

The meeting on air pollution, climate change and and environmental policy has been held since 1999.