China said Monday it had asked Japan not to host an annual meeting organised by an exile group championing the rights of ethnic Uighurs.

The World Uyghur Congress (WUC) represents the mostly Muslim ethnic group that inhabits China's restive western Xinjiang region and is holding its general assembly in Tokyo next month.

"We have launched a representation with the Japanese side to take measures to prevent such an organisation from using Japanese territory to engage in activities splitting China," said Chinese foreign ministry spokesman Liu Weimin.

"They (the WUC) carry out activities undermining China's sovereignty and territorial integrity."

The WUC meeting will be held May 14 to 17, when "some hundreds of ethnic Uighurs from around 20 countries will gather in Tokyo to call for the right of self-determination," Ilham Mahmut, president of Japan Uyghur Association told AFP.

Exiled Uighur leader Rebiya Kadeer, who is based in the United States, will attend the congress, which will be held for the first time in Asia, he said.

The first and the second meetings were held in Munich in Germany and the third was held in Washington, he added.

Many Uighurs complain that they are the victims of state-sanctioned persecution and marginalisation in their homeland, aided by the migration of millions of Han Chinese into the territory.

The resulting ethnic tensions have led to sporadic flashes of violence in the Xinjiang region, which is home to nine million Uighurs.