Rebiya Kadeer, a prominent Uighur political activist, will join world leaders at the annual G-20 Summit in Osaka, Japan, later this month despite protest by China, the Japan Times reported on Sunday.
United States-based Kadeer, who has been issued a visa by Tokyo despite repeated calls from Beijing to not to do so, plans to protest against alleged human rights violations by the Chinese government, the newspaper said.
Kadeer's stay also is expected to coincide with that of Chinese President Xi Jinping, who will be attending the Summit.
Xinjiang Uygur Autonomous Region (XUAR), the far-western province of China, is home to around 10 million Muslim-majority Uighurs.
Beijing has been criticised for setting up of detention camps in Xinjiang and alleged oppressive treatment of the ethnic group, which the Chinese government has described as "education training centres" to help stamp out "extremism" and provide people new skills.
Kadeer, a former president of the World Uighur Congress and current chief of the Free Indo-Pacific Alliance -- a group that represents exiled minorities including Tibetans -- fled China after being labelled a separatist and now lives in the US.
According to Japanese government sources, the visa was applied for on June 7 and issued Wednesday on the grounds that the Uighur activist had already travelled to Japan more than 10 times, and that there was no legal reason to keep her from doing so again.
Kadeer's supporters had said on Friday that the process for the visa took longer this time than the previous visas, which were issued within a week.
The government sources were quoted as saying that Beijing had asked Tokyo in December to handle the matter "appropriately." The request was made directly to the office of Prime Minister Shinzo Abe by a senior official from China's Ministry of State Security.
( With inputs from ANI )