The chair of a US House committee on Wednesday sent letters to six American universities, including Stanford and Carnegie Mellon, requesting information about their policies on Chinese nationals, in the latest congressional attempt to curb the flow of Chinese students to the US over national security concerns.

The letters asked the universities’ presidents to provide detailed information about their entire Chinese student populations by April 1, including the names of the universities the students previously attended, their sources of tuition, and the types of research and university programmes they participate in.

“America’s student visa system has become a Trojan horse for Beijing,” Moolenaar added. “If left unaddressed, this trend will continue to displace American talent, compromise research integrity and fuel China’s technological ambitions at our expense.”