The US said human rights violations like China's treatment of Muslims has not been seen since the 1930's

The US State Department on Wednesday slammed human rights violations in China, saying the sort of abuses it had inflicted on its Muslim minorities had not been seen "since the 1930s."

US Secretary of State Mike Pompeo highlighted abuses in Iran, South Sudan, Nicaragua and China in the department's annual "Country Reports on Human Rights Practices," but told reporters that China was "in a league of its own when it comes to human rights violations."

"For me, you haven't seen things like this since the 1930s," Michael Kozak, the head of the State Department's human rights and democracy bureau told the same briefing, referring to abuses of China's Muslim minority in the Xinjiang region.

"Rounding up, in some estimations ... in the millions of people, putting them into camps, and torturing them, abusing them, and trying to basically erase their culture and their religion and so on from their DNA. It's just remarkably awful."

"It is one of the most serious human rights violations in the world today," he said.

While Kozak did not elaborate on his comment about the 1930s, he was apparently referring to the policies of persecution of Hitler's Germany and Stalin's Soviet Union.

China had initially denied there even were camps, Kozak said, adding its explanation now that they were for voluntary labour training "does not match the facts."

"But at least we're starting to make them realize there is a lot of international scrutiny on this," he said.

China's Embassy in Washington did not respond to a request for comment on the report, which comes at a time of closely-watched trade negotiations between the United States and China aimed at resolving a tit-for-tat tariffs dispute.

Xinjiang Governor Shohrat Zakir said on Tuesday that China was running boarding schools, not concentration camps, in the country's far western region as the US ambassador for religious freedom called the situation there "completely unacceptable," and said sanctions against Chinese officials under the Global Magnitsky Act remained a "possibility."

The administration of President Donald Trump has weighed sanctions against senior Chinese officials in Xinjiang, including the Communist Party boss there, Chen Quanguo, who as a member of the powerful politburo is in the upper echelons of China's leadership. Beijing has warned of retaliation if Washington were to target Chen and the administration has yet to act despite complaints from US lawmakers.

The State Department report said Chen had replicated in Xinjiang policies similar to those credited with reducing opposition to Communist Party rule in Tibet, where he was previously stationed.

Intensified detention campaign

The report said that in the past year, China had significantly intensified its campaign of mass detention of members of Muslim minority groups in Xinjiang.

It said authorities there were reported to have arbitrarily detained from 800,000 to possibly more than two million Uighurs, ethnic Kazakhs and other Muslims in camps with the aim of erasing religious and ethnic identities.

Pompeo said the Iranian government had killed more than 20 people and arrested thousands without due process for protesting for their rights "continuing a pattern of cruelty the regime has inflicted on the Iranian people for the last four decades."

In South Sudan, he said, military forces had inflicted sexual violence against civilians based on their political allegiances and ethnicity, while in Nicaragua, peaceful protesters had faced sniper fire and government critics had "faced a policy of exile, jail or death."

The report also revised its usual description of the Golan Heights from "Israeli-occupied" to "Israeli-controlled."

A separate section on the West Bank and Gaza Strip, areas that Israel captured along with the Golan Heights in a 1967 war in the Middle East, also did not refer to those territories as being "occupied," or under "occupation."

In Myanmar, the report said press freedom had declined and journalists had reported that self-censorship had became more pronounced because of the trial and conviction of Reuters journalists Wa Lone and Kyaw Soe Oo, who were jailed for seven years after being convicted in September of breaking a colonial-era official secrets law.

The reporters had been working on a Reuters investigation into the killing of 10 Muslim men and boys by security forces and Buddhist civilians in Myanmar's Rakhine State.

Responding to the US report, Amnesty International criticized the Trump administration for engaging with governments, including that of Saudi Arabia, "regardless of their human rights record, if doing so will advance US interests."

The State Department report highlighted Saudi Arabia's killing of journalist Jamal Khashoggi and said it had not provided a detailed explanation of the direction or progress of the investigation.

A CIA assessment and a Senate resolution have blamed Saudi Crown Prince Mohammed bin Salman for ordering the killing, something Saudi officials deny, but President Donald Trump has said Washington will remain a "steadfast partner" of Saudi Arabia even though the prince may have known about the plan.

Republican and Democratic US senators said this month they were frustrated with the Trump administration's failure to provide more information about the case and vowed to push for a stronger response.