The US space agency NASA has blocked Chinese citizens with valid US visas from its facilities, a move that effectively bars them from working at one of the most respected space research centers.

Chinese nationals, who could only work at NASA as contractors or students contributing to research, found out on September 5 that they had lost all access to NASA's systems and facilities, Bloomberg news reported, citing sources.

NASA confirmed that Chinese nationals would be restricted from using the agency's facilities, materials, and networks to ensure the security of our work. China's accelerated space program has alarmed the US and ramped up the race between the two largest economies.

Chinese astronauts are already excluded from the International Space Station (ISS) due to restrictions that bar NASA from sharing its data with China. The latest action by NASA only exacerbates the decline in scientific cooperation between the two nations, fueled by national security concerns.

As both Beijing and Washington compete for technological dominance, they have grown increasingly wary of one another, making it more challenging for Chinese students, particularly those studying science and technology, to obtain visas or enter the US once they secure a visa.

There have been several cases recently in the US of alleged espionage involving Chinese nationals, particularly scientists, being scrutinized for their activities.

The exact notice that NASA provided to Chinese nationals who were working for the agency is unclear, but reports indicate they found themselves suddenly barred from access to data systems and participation in all work-related meetings, both in person and virtually.

NASA's press secretary, Bethany Stevens, confirmed to news outlets that they had taken internal actions concerning Chinese nationals, including restricting physical and cybersecurity access to our facilities.

China's ambitions in space are no secret, with both nations racing to send crews to the moon. NASA's acting administrator, Sean Duffy, emphasized at a recent press conference, We're in a second space race right now... The Chinese want to get back to the moon before us. That's not going to happen.

Chinese officials have previously dismissed US concerns, framing their space exploration as a collective mission for humanity. Recently, during a US Senate hearing, lawmakers highlighted the urgent need for the US to reestablish its presence on the moon before China. Senator Ted Cruz warned, If our adversaries achieve dominant space capabilities, it would pose a profound risk to America... the stakes could not be higher.

This space race goes beyond mere exploration; it encompasses who can control the moon's resources, including rare minerals and helium, which have significant ramifications for technology and industry.