China's top legislature has strongly condemned the enactment of a Xinjiang-related bill in the United States, calling it a brutal action to interfere in China's internal affairs.

The White House issued a statement on Wednesday saying US President Donald had signed the so-called Uygur Human Rights Policy Act of 2020 into law.

The move seriously violated international laws and the basic principles of international affairs, the Foreign Affairs Committee of the National People's Congress, China's top legislature, said in a statement issued on Thursday.

Xinjiang has always been China's main battlefield against terrorism and religious extremism, it said, with the penetration of religious extremism from abroad having led to frequent terrorist attacks in the past.

Between 1990 and the end of 2016, thousands of terrorist incidents occurred in the region, causing a large number of casualties, the statement said, adding that Xinjiang has introduced a series of counterterrorism and deradicalization measures, including setting up vocational and training centers, in accordance with the law.

The centers have provided courses on Mandarin, laws, vocational skills and deradicalization programs for people influenced by religious extremism and terrorism. According to the regional government, all the trainees in the centers graduated in December.

As a result, the region has recorded no terror-related incidents for more than three years, which has protected Xinjiang people's livelihoods and been supported by Chinese people and the international community, the statement said.

Xinjiang issues are never about human rights, ethnic groups or religions, it said, and are instead about fighting terrorism and extremism. The US was also a victim of terrorism, so it should understand China's measures. However, it viciously attacked the efforts China made to fight terrorism and extremism in the name of human rights and adopted a double-standard on counterterrorism issues, the statement added.

Xinjiang issues are China's internal affairs, which should never be interfered with by external forces. The committee urged the US to stop such interference and actions that were damaging China-US relations.

China also expressed its strong opposition after the bill was approved by the House of Representatives in December, with many official organs saying it was "packed with lies".