A display for facial recognition and artificial intelligence is seen on monitors at Huawei's Bantian campus on April 26, 2019 in Shenzhen, China.

The head of Human Rights Watch said Tuesday the Chinese government has not only constructed "an Orwellian high-tech surveillance state" at home but is using its growing economic clout to silence critics abroad.

Kenneth Roth accused China of carrying out "the most intense attack on the global system for enforcing human rights since that system began to emerge in the mid-20th century."

He warned that if human rights aren't defended, the world could face "a dystopian future in which no one is beyond the reach of Chinese censors" and a global rights system so weakened that it can no longer serve "as a check on government repression."

Roth held a news conference at the United Nations Correspondents Association in New York after being denied entry to Hong Kong, where he had been scheduled to release the rights group's annual report. It begins with his keynote essay entitled, "China's Global Threat to Human Rights."

Chinese Foreign Ministry spokesman Geng Shuang said Monday: "It is China's sovereignty to allow one's entry or not."

He indicated that Human Rights Watch is among organizations that support and instigate "anti-China activists ... to engage in radical violent crimes, and incite separatist activities hyping Hong Kong independence." He added: "These organizations deserve sanctions and must pay a price."

U.N. spokesman Stephane Dujarric, asked Tuesday about Roth's denial of entry to Hong Kong, said: "In principle, we support the rights and work of human rights defenders around the world."

Chinese diplomat Xing Jisheng, who attended the U.N. press launch, spoke at the end calling the report "very prejudicial," saying it has "fabrications" and telling journalists "we completely reject the content."

Xing said the government has made every effort to advance human rights in China and any human rights report that doesn't mention that 700 million Chinese people have escaped from poverty over the last 40 years "fails to be balanced and neutral."

Roth responded saying the report does mention "the emancipation of the Chinese people" and asked: "What did we get wrong? If there's something wrong we will change it."

In the essay, Roth said the Chinese Communist Party is "worried that permitting political freedom would jeopardize its grasp on power" and "is running scared of its own people."

"The consequence under President Xi Jinping is China's most pervasive and brutal oppression in decades," he said.

Roth pointed to the closure of the "modest opening" that existed briefly in recent years for Chinese people to express themselves, civic groups shut down, independent journalism gone, online conversations curtailed, ethnic and religious minorities facing severe persecution, and severe challenges to Hong Kong's limited freedoms under "one country, two systems."

To avoid a global backlash against its surveillance, internet censorship and oppression at home, Roth said the government is trying to undermine international institutions designed to protect human rights.

It is increasingly targeting critics of rights violations, "whether they represent a foreign government, are part of an overseas company or university, or join real or virtual avenues of public protest."

Using its economic clout and influence and sometimes its veto in the U.N. Security Council, Roth said, China has sought to block United Nations measures "to protect some of the world's most persecuted people."

He cited China's failure to support Syrian civilians facing indiscriminate airstrikes by Russian and Syrian planes, Myanmar's Rohingya Muslims who faced murder, rape and arson at the hands of Myanmar's army, Yemen's civilians facing bombardment by a Saudi-led coalition, or Venezuelans suffering "economic devastation due to the corrupt mismanagement of Nicolas Maduro."

Human rights organizations say up to 1 million ethnic Uighur Muslims in China's western Xinjiang region have been detained in camps where they are subjected to political indoctrination and pressured to give up their religion. The Associated Press reported last year that some are forced to work in factories, and tracked clothing made in one camp to an American sportswear company.

Roth stressed that "no other government is simultaneously detaining a million members of an ethnic minority for forced indoctrination and attacking anyone who dares to challenge its repression."

"And while other governments commit serious human rights violations, no other government flexes its political muscles with such vigor and determination to undermine the international human rights standards and institutions that could hold it to account," he said.

Roth said the report shows that China isn't the only threat to human rights, pointing to serious violations by the warring parties in Syria and Yemen.

He also cited "autocratic populists" who come to power by demonizing minorities and retain it by attacking independent journalists, judges and activists who try to provide checks and balances on their rule.

"Some leaders, such as U.S. President Donald Trump, Indian Prime Minister Narendra Modi, and Brazilian President Jair Bolsonaro, bridle at the same body of international human rights law that China undermines, galvanizing their publics by shadow boxing with the `globalists' who dare suggest that governments everywhere should be bound by the same standards," Roth said.

He lamented that some governments that once could be counted on to sometimes defend human rights "have largely abandoned the cause."

But even against this backdrop, Roth said, China stands out.

"The result for the human rights cause is a `perfect storm' — a powerful centralized state, a coterie of like-minded rulers, a void of leadership among countries that might have stood for human rights, and a disappointing collection of democracies willing to sell the rope that is strangling the system of rights that they purport to uphold," he said.

Nonetheless, Roth said "much can still be done to defend human rights worldwide from Beijing's frontal attack."

He urged governments, companies, universities, international institutions and others to stand with people in China and from China who are struggling to secure their rights.

Roth said governments and international financial institutions should offer human rights-respecting alternatives to China's "no strings" loans and development aid. He said government should "deliberately counter China's divide-and-conquer strategy for securing silence about its oppression." And he said universities and companies should promote "codes of conduct" with strong standards for dealing with China