China said Monday it would take "countermeasures" if the US calls for a diplomatic boycott of the Beijing Winter Olympics, hours after unsubstantiated reports that the Biden administration may announce such a boycott this week.

CNN and NBC reported Sunday that the diplomatic boycott — no US government officials attend the Games, but athletes compete — could be announced this week, following President Joe Biden's November statement that he was "considering" it.

Biden faces domestic pressure to speak out against China's human rights violations, particularly in Xinjiang, where the US government has declared that mistreatment of the Uyghur ethnic community constitutes genocide.

Beijing stated in reaction to rumors that such a move would be "pure grandstanding."

"I want to emphasize that the Winter Olympic Games are not a platform for political posturing and manipulation," foreign ministry spokesperson Zhao Lijian said Monday during a routine press briefing, asking the US to avoid "hyping" the boycott.

"If the US is adamant about getting its way, China will respond resolutely," Zhao warned.

According to campaigners, at least one million Uyghurs and other Turkic-speaking, predominantly Muslim minorities have been detained in camps in Xinjiang, where China is also accused of forcefully sterilizing women and enforcing forced labor.

The Winter Olympics, which will take place six months after the pandemic-affected Tokyo Summer Games, will be hosted from February 4 to 20 in a "closed loop" bubble due to Covid-19 restrictions.