BEIJING >> An official from China’s far west Xinjiang region accused former U.S. Secretary of State Mike Pompeo on Monday of trying to undermine Beijing’s relations with new President Joe Biden by declaring that China’s actions against the Uighur ethnic group are “genocide.”

Xu Guixiang, a spokesperson for Xinjiang’s Communist Party, spoke at a tightly controlled media briefing, the latest in a Chinese effort to counter Western accusations of rights abuses in the region.

“Why is he putting on such a show, such a farce, telling the lie of the century?” Xu said. “He wants to plant land mines and set up obstacles to dialogue with the next U.S. administration.”

Since 2016, China has swept a million or more Uighurs and other predominantly Muslim minorities into prisons and indoctrination camps that the state calls training centers, according to estimates by researchers and rights groups.

People have been subjected to torture, sterilization and political indoctrination in addition to forced labor as part of an assimilation campaign, according to former residents and detainees, as well as experts and leaked government documents. China denies any abuses and says the steps it has taken are necessary to combat terrorism and a separatist movement.

The Biden administration is formulating its policies toward China, which many analysts see as America’s largest geopolitical challenge.

Last week, U.S. Secretary of State Antony Blinken reiterated on his first day in office that he believed genocide was being committed against Xinjiang’s ethnic minorities, signaling that Biden plans to continue some of former President Donald Trump’s tough stances against Beijing.

Over the course of two hours, Xu and others, including an imam and former center “trainees,” took turns denying forced sterilization, forced labor, restrictions on religion and other allegations.

They did not name Biden or Trump and instead trained their ire at Pompeo. Xu called him “hysterical,” a “rat” and “the worst secretary of state in history.”

Pompeo said one of the main reasons for the genocide designation was widespread forced birth control among the Uighurs, which The Associated Press documented last year as well as researcher Adrian Zenz.

Another reason he cited was forced labor. AP reporters found that Uighur workers at OFILM, an Apple supplier nearly 3,200 kilometers (2,000 miles) from Xinjiang in the eastern city of Nanchang, were not allowed to leave their factory compound freely and could only come out on rare, chaperoned trips.

Asked about OFILM, Xinjiang government spokesperson Elijan Anayat said that workers were employed voluntarily and that their labor rights were protected.

Yusupjan Yasinjan, introduced as a former OFILM worker, said he had signed a contract to work there. He described working conditions as good, with halal meals, ample salaries and free “hotel-like” accommodations, and added that he could “ask for leave.”

Yasinjan did not respond directly to whether he was allowed to leave the factory compound freely. Officials did not allow reporters to ask follow-up questions.

On detention centers, Anayat repeated government statements that the camps had been closed and all the students had graduated.

However, satellite imagery and interviews with former Xinjiang residents indicate that the region’s vast detention apparatus remains in place.

While some detainees have been released, others have been given long prison sentences or forced to work in factories, according to relatives in Kazakhstan and Turkey. Satellite imagery shows that some of the camps have closed and others have been expanded or converted into prisons, analysts say, as Chinese government statistics show that Xinjiang’s incarceration rates have jumped significantly in recent years.

Former residents who have fled Xinjiang say their relatives still in the region have cut contact with them out of fear, as authorities have targeted those with overseas ties for detention.

Anayat said those who had left weren’t able to contact their relatives because they had misdialed their phone numbers or joined Uighur independence groups. In certain cases, he said, it was because the relatives had been detained for suspected criminal activities.

Three attendees approached after the news conference declined to give business cards or contact information. An official hovering nearby said all follow-up questions had to be routed through the Foreign Ministry.

“Sorry,” said Gulnar Uful, an official with Xinjiang’s bureau of agricultural machinery, declining to give her phone number as she hurried out of the room. “It’s not convenient for me to give it to you.”