The US has revoked visas for more than 1,000 Chinese nationals over security risks.
The acting head of the US Department of Homeland Security, Chad Wolf, said earlier that Washington was blocking visas "for certain Chinese graduate students and researchers with ties to China's military fusion strategy to prevent them from stealing and otherwise appropriating sensitive research".
In a speech, Wolf repeated US charges of unjust business practices and industrial espionage by China, including attempts to steal coronavirus research, and accused it of abusing student visas to exploit American academia.
Wolf said the United States was also "preventing goods produced from slave labour from entering our markets, demanding that China respect the inherent dignity of each human being," an apparent reference to alleged abuses in China's Xinjiang region.
A State Department spokeswoman said the visa action was being taken under a proclamation President Donald Trump announced on May 29 as part of the U.S. response to China's curbs on democracy in Hong Kong.
"As of September 8, 2020, the Department has revoked more than 1,000 visas of PRC nationals who were found to be subject to Presidential Proclamation 10043 and therefore ineligible for a visa," she said.