Japan's parliament on Tuesday passed a rare resolution expressing concern about rights issues in China, including the treatment of its Uyghur Muslim population and the city of Hong Kong, days before the Beijing Olympics open.

The wording of the resolution proposed by a bipartisan group was reportedly watered down after lengthy discussions, avoiding directly accusing Beijing of rights abuses.

But it comes at a time of increased focus on China's rights record as the country prepares to host the Beijing Winter Olympics this month.

Tokyo has sought to walk a careful line in its approach to China, balancing the pressure put on Beijing by close ally Washington. The United States and China are Japan's biggest trading partners.

A majority vote in the lower house approved the resolution, which expresses "serious concerns over the human rights situations" in China's Xinjiang region, Tibet, Hong Kong and Inner Mongolia.

The resolution also calls on Japan's government to engage constructively on rights issues in China.

In response, Beijing slammed the resolution as a "serious political provocation".

The resolution "grossly interferes in China's internal affairs," said foreign ministry spokesman Zhao Lijian, adding that "China reserves the right to take further measures".

The parliamentary resolution comes at a time of increased focus on China's rights record
The parliamentary resolution comes at a time of increased focus on China's rights record AFP / CHARLY TRIBALLEAU

China has long denied accusations over its treatment of Uyghurs and other mostly Muslim Turkic people, including a US allegation it committed genocide.

Experts have estimated that more than one million people are incarcerated in camps in the Xinjiang region home to the minority.

Likewise, Beijing has denied claims that Tibetans live under strict surveillance with the threat of jail or abuse for any signs of a non-Chinese identity, including possessing images of the Dalai Lama -- their exiled spiritual leader.

On Hong Kong, Japan has repeatedly expressed "grave concerns" over the former British colony's electoral system as China ramped up control of the financial hub, prompting huge pro-democracy protests.

In December last year, Japan said it would not send government representatives to the Beijing Olympics as it called on China to respect human rights and the rule of law.

The move came after the United States, Britain, Australia and Canada announced diplomatic boycotts of the Games over what they consider to be widespread rights abuses by China.

Their boycott stops short of not sending athletes to the Winter Games, which start on February 4.

But Beijing has warned the four Western nations would "pay the price" for the US-led campaign.

Japan, which hosted the virus-postponed Tokyo Olympics last year, is sending Tokyo 2020 chief Seiko Hashimoto and Japanese Olympic Committee head Yasuhiro Yamashita to the Beijing opening ceremony.