Senior Pentagon officials are increasingly concerned about the fact that the Chinese army can track and target American satellites from a secret deep-space tracking facility in Las Lajas, Argentina.

In a testimony before the US Congress on 7 February, Admiral Craig Faller, the new commander of the US Southern Command, warned against the rapid expansion of China to South America.

Fallar told lawmakers that China actively supports active autocratic governments in Cuba, Nicaragua and Venezuela, and that they apply predatory lending to the entire continent. He said that Beijing has played an important role in the development of infrastructure such as a secret antenna in the deserts of Patagonia.

American intelligence services have been following the development of the facility since its inception.

In the last few years, a gigantic 16-storey antenna has been built on a 200-hectare site in the west of the country, on the north side of Patagonia.

An 8-foot high-security fence surrounds the space station, operates with limited surveillance from Argentine officials, experts say.

Brian Weeden, a space policy and security analyst at the Secure World Foundation, indicated that the US military is using antennas similar to those in Argentina.

"Unless something else is specific, it's a little bit of the pot that turns the kettle black," he said.

"For me there is no specific evidence, except that it happens to be Chinese, which indicates that it is nefarious."

However, US military officials are concerned that the antenna may be used to collect sensitive information about the position and activity of American spy satellites.

"Beijing could be in violation of the terms of its agreement with Argentina to only carry out civilian activities and may have the ability to monitor and possibly use space activities from the US, allies and partners," said Faller, who said briefly in the Pentagon served as the highest military assistant to former Defense Secretary James Mattis.

Experts point out that Beijing's claim to use the facility for peaceful purposes only can be deceptive, since the Chinese national space agency (currently managing the facility) is closely linked to the People's Liberation Army.

Frank Rose, who served as US assistant secretary of the state for arms control from 2014 to 2017 and is currently a senior fellow with the Brookings institution, said the placement of the antenna provides China with critical space coverage on the western hemispheres.

"It's about bridging certain jobs, there's a reason why the US has satellite stations around the world – it gives you global coverage," Rose said, "you can not get worldwide coverage from China."

Evan Ellis, an instructor of Latin American studies at the Strategic Studies Institute of the US Army War College, said that the primary goal of the antenna could actually be space research. The features of the facility are "in line with what the Chinese say it is," he said, noting that the location in the desert of Patagonia "has a certain sense" because scientists need antennas around the world for deep space observations.

The staff that manages the facility is either active or former Chinese military, which is not inherently outrageous, given how closely the army is connected to the Chinese space program, Ellis said.

Ellis said there is a chance that the facility could be used to collect sensitive data on commercial and military satellites that occasionally pass overhead.

With the lack of openness and supervision of the secret Patagonian Space Station Facility, it is a mystery what exactly the Chinese are doing in the Western Hemisphere.