China will force a French journalist who criticised its treatment of its Muslim Uighur minority to leave the country, her employer, the weekly l'Obs news magazine, says.

The press visa of Ursula Gauthier, the magazine's Beijing correspondent, expires on December 31 and Beijing has refused to grant an extension, saying a report she wrote supports acts of violence by Uighurs that China considers terrorist activity.

The story, dated November 18, suggested that China was using last month's Paris attacks to justify crackdowns on Uighur people in northwest China's Xinjiang region.

Hundreds have been killed in recent years in the region, beset by ethnic tensions that Uighur groups blame on repressive government policies while China denies any human rights abuses and says it faces a campaign from Islamist radicals and separatists.

L'Obs said Gauthier was the subject of editorials in state-controlled media and even death threats after her article was published.

A Chinese foreign ministry spokesman, Lu Kang, said the article "openly supports terrorist activity, the killing of innocents and has outraged the Chinese public". His comments appeared in a question-and-answer posted on the ministry's website on Saturday.

Lu added that because Gauthier did not make a public apology, she could not work in China.

L'Obs, which changed its name from Le Nouvel Observateur in October 2014, said on Friday it stood by its correspondent.

It wrote in an editorial that China's refusal to extend her visa represented a "major incident" at a time when France and China were strengthening their economic, cultural and diplomatic ties.

The French foreign ministry on Friday issued a terse statement in which it regretted that her visa was not renewed. "France would like to remind how important it is for journalists to be able to work everywhere in the world," it said.