It occurs as China gears up to send a crewed mission to land and potentially establish a habitat on the moon, about which the Trump administration has expressed increasing alarm.

The new policy began September 5 and its effects have since rippled across the sprawling agency, according to two people at NASA who spoke on the condition of anonymity for fear of retribution.

The change affects hundreds of scientists and researchers, many of whom are funded by NASA to conduct their work in climate science, space and other disciplines, the sources said.

A NASA spokesperson put the number of those affected at less than 100.

It is not clear if there was a specific incident that prompted this crackdown.

When CNN asked NASA why these steps were taken, NASA’s press office sent a post on X with a clip of a recent appearance by acting administrator Sean Duffy on Fox Business.

“China is NOT going to the moon with good intentions,” the post from Duffy reads.

“America will get there FIRST, preserving peace for both the US and our international partners.”

Chinese nationals are no longer allowed to have physical access to NASA facilities, to join Zoom calls with their NASA colleagues or access the agency’s supercomputing resources.

Supercomputing work is essential for those who are studying climate change in particular.

The limitations placed on these researchers is disrupting NASA’s work and could stymie the careers of younger Chinese researchers who came to the US to advance their scientific work, as well as benefit the space agency through their findings, the sources said.

The restrictions also apply to attendance at NASA-funded meetings, both in person and online.

They are resulting in additional disruptions amid what has already been a turbulent time for NASA employees since the administration has targeted the agency for steep budget cuts and reductions in personnel.

“The internal action taken at NASA pertaining to Chinese nationals, including physical and cybersecurity restrictions, are a separate matter from the Executive Order,” the spokesperson told CNN.

Today, NASA press secretary Bethany Stevens was more specific about the sweeping nature of the restrictions imposed on Chinese citizens who have US visas, telling CNN: “NASA has taken internal action pertaining to Chinese nationals, including restricting physical and cybersecurity access to our facilities, materials, and network to ensure the security of our work.”

The new restrictions, reported earlier by Bloomberg News, come at a time of heightened competition between the US and China both on Earth and in the new space race.

China has been advertising plans to land Taikonauts — or Chinese astronauts — on the lunar surface for the first time by 2030, competing with NASA’s plan to return its own astronauts to the moon’s surface as soon as mid-2027.

Acting NASA Administrator Sean Duffy, a close Trump ally who is also the Secretary of Transportation, caused a stir in early August by saying he has directed the US space agency to fast-track plans to put a nuclear reactor on the moon to generate power for a future permanent settlement on the lunar surface.

“We’re in a race to the moon, in a race with China to the moon,” Duffy told reporters at the time, warning that if another country beat the US, that nation could declare a “keep-out zone” that could thwart NASA’s moon base plans.

These charged discussions about racing China to the moon come as NASA is set to lose thousands of employees and could lose billions in funding.

At least 4000 people are taking deferred resignation offers from the Trump administration, according to two sources familiar with the matter.

The president’s proposed 2026 budget would also slash NASA’s overall funding by 24 per cent.

While funding for the agency’s Artemis moon landing program has remained largely intact, the cuts would include a nearly 50 per cent reduction in science funding.

Politicians on both sides of the aisle have expressed a desire to secure American supremacy in space.

“Make no mistake, we are in a new space race with China,” Republican Texas Senator Ted Cruz, the chair of the Senate Committee on Commerce, Science, and Transportation, said at a committee hearing last week.

“Space is no longer reserved simply for peaceful exploration.

“It is today a strategic frontier with direct consequences for national security, economic growth and technological leadership.”

Cruz’s Democratic colleague, Senator Maria Cantwell of Washington, the committee’s ranking member, added she viewed continued investments in space technology to be “critical to our future economic and national security”.

“We know we need to go back to the moon, and we know we need to go there before China establishes a permanent presence,” Cantwell said.