The United States has announced a diplomatic boycott of the 2022 Beijing Winter Olympics, a calibrated rebuke of China's human rights record that stops short of preventing US athletes from competing.

The decision comes after Washington spent months wrangling with what position to take on the Games, hosted in February next year by a country it accuses of perpetrating "genocide" against Uyghur Muslims in the northwestern Xinjiang region.

There was no immediate reaction from Beijing, but the Chinese foreign ministry had earlier threatened "resolute countermeasures" to any such boycott.

The decision was broadly welcomed by rights groups and politicians in the US, where President Joe Biden has been under pressure to speak out against Chinese rights abuses.

White House Press Secretary Jen Psaki on Monday said the administration would send no diplomatic or official representation to the Games given China's "ongoing genocide and crimes against humanity in Xinjiang and other human rights abuses." 

Sending official representation would signal that the Games were "business as usual," Psaki said.

"And we simply can't do that."

"The athletes on Team USA have our full support. We will be behind them 100 percent as we cheer them on from home," she added.

The International Olympic Committee said the sending or not of officials was a "purely political decision for each government, which the IOC in its political neutrality fully respects."

The announcement "also makes it clear that the Olympic Games and the participation of the athletes are beyond politics and we welcome this," an IOC spokesperson said.

- Diplomatic high-wire act -

US-China relations hit a low point under Biden's predecessor Donald Trump, with a massive trade war and incendiary debate over how the Covid-19 virus first emerged in the Chinese city of Wuhan.

Biden has sought to re-engage with Beijing, while at the same time focusing on strengthening traditional US alliances to counter China's ever-growing economic clout and military presence across the Indo-Pacific region.

The Olympics boycott is part of a complex diplomatic balancing act. 

Biden's administration has left Trump-era trade tariffs on China in place and continues to order naval patrols through sensitive international sea lanes that China is accused of trying to bring under its control.

However, with Biden also emphasizing the need for dialogue, critics on the right say he is being too soft.

This makes the looming Olympic Games a political flashpoint.

Members of Team USA, their coaches, trainers and other staff will still receive consular and diplomatic security assistance, State Department spokesman Ned Price said.

When asked about calls for private businesses to end any Winter Games sponsorships, he stressed that the decision was up to them.

"It is not in this country -- unlike other countries -- the role of the government to dictate the practices that the private sector should adopt," Price said.

- 'Powerful rebuke' -

Campaigners say that at least one million Uyghurs and other Turkic-speaking, mostly Muslim minorities have been incarcerated in camps in Xinjiang, where China is also accused of forcibly sterilizing women and imposing forced labour.

Bob Menendez, the chair of the powerful US Senate foreign relations committee, welcomed the diplomatic boycott as "a powerful rebuke" of the "genocide in Xinjiang."

He and top House foreign affairs Democrat Gregory Meeks called for other countries to follow the US lead.

Meeks warned the international community should not be helping China "whitewash its atrocities against Uyghurs and other minorities."

But Republican Senator Tom Cotton called it a "half measure, when bold leadership was required."

"The United States should fully boycott the Genocide Games in Beijing," he said in a statement.

The last full boycott of the Olympics by the US was in 1980, when President Jimmy Carter withdrew in protest against the Soviet Union's invasion of Afghanistan.

Human Rights Watch called the Biden administration's decision "crucial" but urged more accountability "for those responsible for these crimes and justice for the survivors."

Earlier Monday Chinese foreign ministry spokesman Zhao Lijian warned the Games were "not a stage for political posturing and manipulation" -- in response to reports a boycott could be imminent.

"If the US is bent on having its own way, China will take resolute countermeasures," he vowed.

Coming just six months after the pandemic-delayed Tokyo Summer Games, the Winter Olympics will be held from February 4 to 20 in a "closed loop" bubble because of Covid-19 restrictions.

"To be honest, Chinese are relieved to hear the news, because the fewer US officials come, the fewer viruses will be brought in," tweeted the Chinese state-owned tabloid newspaper, Global Times.