China urges students to weigh 'risk' of studying in US

The warning comes as negotiations to resolve the trade spat have stalled and Washington pushed back against what it says is Beijing's aggressive militarisation of the disputed South China Sea.

In recent months US officials and lawmakers have voiced concerns that Chinese students and academics could be used for espionage purposes by the Communist government.

The Chinese education ministry in a statement said students applying to US universities should brace themselves for visa troubles and "strengthen risk assessment... and make relevant preparations".

Chinese students and academics have recently experienced visa restrictions, delays in obtaining them, and visas with shorter duration, according to the ministry.

China is the biggest source of international students on US campuses, with 360,000 of them last year, or a third of the foreign student body, with many paying full tuition.

Chinese students contributed USD 14 billion to the US economy in 2017, the official Xinhua news agency estimated last month, citing US official data.

China's foreign ministry spokesman Geng Shuang on Monday said the US had been setting "unnecessary obstacles" to people-to-people exchanges between the two countries.

"This has been widely opposed by the education circles in China and the United States, as well as by (Chinese) students studying abroad (in the US)," he said.

US complaints about technology and intellectual property theft by China have been a major bone of contention in the trade war between the two countries.

FBI director Christopher Wray said in April that Beijing had used Chinese graduate students and researchers, among others, in its economic espionage efforts in the United States.

"China has pioneered a societal approach to stealing innovation in any way it can from a wide array of businesses, universities and organisations," Wray said.

"They're doing it through Chinese intelligence services, through state-owned enterprises, through ostensibly private companies, through graduate students and researchers, through a variety of actors all working on behalf of China."

Last month, Republicans in the US Congress introduced legislation aimed at barring Chinese military scientists from obtaining visas to study or work in the United States.

The bills in the House and Senate would compel the White House to identify a list of research and scientific institutions that the president determines are affiliated with or funded by the People's Liberation Army.

The PLA Visa Security Act would prevent people currently or formerly employed or sponsored by such entities from entering the United States on student or research visas.

The New York Times reported in April that the United States has started to bar some Chinese academics from the country if they are suspected of having links to Chinese intelligence agencies, with 30 scholars having their visas cancelled or put under review in the past year.

China's state-run Global times has published accounts from several Chinese academics saying their 10-year visas to the US were cancelled, with officials citing concerns about links to Chinese intelligence.

US scholar Michael Pillsbury, who advises US President Donald Trump on China, said his visa to enter China for a forum earlier this year was blocked in apparent retaliation.