Lawmakers in Washington have tabled legislation in Congress that would tighten restrictions around study or research visas for Chinese nationals with ties to the military.
The new rules proposed by a group of Republicans would prohibit anyone employed or sponsored by China's People's Liberation Army (PLA) from receiving student or research visas to the United States.
The bill, sponsored by Republicans Senators Chuck Grassley, Tom Cotton, Ted Cruz, Marsha Blackburn, and Josh Hawley, would mandate the drawing up of a list of PLA-linked institutions, and the adding of their employees to a visa blacklist.
A companion bill was introduced in the House of Representatives by Representative Mike Gallagher, Reuters reported.
The move comes amid heightened concern in the U.S. that China and other foreign governments are exploiting U.S.-funded research to acquire intellectual property.
However, U.S. and university officials have warned against a third "Red Scare" harking back to the McCarthyist purges of the 1950s.
U.S.-based legal scholar Teng Biao said Chinese infiltration of the United States has been going on for a long time.
"China has been engaging in infiltration in the United States, and exporting its model of dictatorship for a long time now," Teng told RFA.
"The United States and other countries have only recently noticed that the Chinese military in particular has made use of opportunities offered by Sino-U.S. exchanges to send students, scholars, and researchers to the United States, where they gather intelligence and steal secrets," he said.
"This is actually a really serious problem, and the U.S. hasn't been taking it seriously enough," Teng said.
He said the moves came after a number of U.S. academics and journalists had been denied visas for China, or forced to leave the country, and could be seen as a form of retaliation.
National security concerns
Chinese political commentator Chen Daoyin said recent concerns over China as a threat to U.S. national security is a major factor driving the bill.
"While the United States still leads or plays a guiding role in the high-tech sector ... China is also at the forefront of certain fields," he said. "It is inevitable that some damage has been done as a result of greater levels of exchange and integration."
"These are national security considerations, and there may be some trade-offs to be made," Chen said.
Chinese foreign ministry spokesman Geng Shuang said the concerns over national security are "unfounded."
"For some time, certain departments and organizations in the United States have been harboring unfounded doubts about the motives of Chinese scholars, students and science and technology personnel in the United States," Geng said.
"[They have been] unreasonably restricting, harassing and setting up various obstacles in the way of normal ... exchanges between the two countries."
Geng said the U.S. should not "politicize or unreasonably restrict" bilateral exchanges.
"We hope that the relevant parties in the U.S. will treat the exchanges between the two sides objectively and fairly, and stop restricting Chinese scholars, students and other personnel from going to the United States," he said.
Last month, a top cancer research center in Texas said it is taking steps to fire three scientists amid concerns that the Chinese government is trying to steal U.S. scientific research, U.S. media reported.
The MD Anderson Cancer Center in Houston, Texas, took the action after receiving e-mails last year from the National Institutes of Health (NIH) outlining conflicts of interests or unreported foreign income linked to five of its faculty members, the Houston Chronicle reported in an article jointly produced with Science Magazine.
The center said it had begun the process of terminating the contracts of three researchers for fear of losing NIH funding, the paper reported.
However, Chinese and Chinese-American communities have hit out at the investigations, saying that they involve racial profiling.
Reported by Lau Siu-fung for RFA's Cantonese Service. Translated and edited by Luisetta Mudie.