The Pentagon's decision to use a commercial satellite operated by a Hong Kong-based and listed company was questioned by a US lawmaker who said the use of China's Apstar-7 satellite "exposes our military to the risk that China may seek to turn off our eyes and ears".
However, a satellite expert has played down the fears, pointing out that it was made by a French company.
The Pentagon uses the satellite to provide communications for its Africa Command.
Use of China's Apstar-7 satellite was approved because it provided "unique bandwidth and geographic requirements" for "wider geographic coverage" requested last May by the US Africa Command, said Lieutenant Colonel Monica Matoush, a Pentagon spokeswoman.
Apstar-7 is operated by APT Satellite Holdings. The state-owned China Aerospace Science & Technology Corp holds 61 per cent of Hong Kong-based APT. The Pentagon contract was disclosed without details at a House Armed Services Committee hearing on Thursday during questioning from congressman Mike Rogers, chairman of the panel that oversees space programmes.
The contract "exposes our military to the risk that China may seek to turn off our 'eyes and ears' at the time of their choosing", Rogers, a Republican, said. "It sends a terrible message to our industrial base at a time when it is under extreme stress" from the automatic US budget cuts known as the sequester.
Matoush said the Defence Information Systems Agency and Africa Command "made an informed risk assessment of operational security considerations and implemented appropriate transmission and communications security and information assurance measures".
She said security of "all signals to and through the Apstar-7 satellite are fully protected with additional transmission security".
Satellite services were leased under a one-year, US$10.6 million contract through US company Artel, Matoush said.
While the Apstar-7 lease expires on May 14, the agency has the option to extend it for up to three more years.
Rogers said he was "deeply concerned a low-level [Department of Defence] agency was able to enter into a contract with a Chinese company to use a Chinese satellite launched by a Chinese missile".
However, Professor He Qisong, of the sea power and defence policy research institute at the Shanghai University of Political Science and Law, said because the Apstar-7 only supports bandwidth for telecommunication there was no need to worry about "so-called military leaks".
"The Apstar-7 was produced by France, one of the US' allies. If there was a security problem, the French would tell the Pentagon first," he said.
"The Apstar-7 just supports bandwidth. It couldn't provide any accurate positioning service similar to the US-controlled Global Positioning System, which is also used by Chinese military and civilian organisations. The US politician just wants to hype up China's threat."
Douglas Loverro, the Pentagon's top space policy official, told the House panel the Apstar-7 lease was the only one available to support an urgent "operational need". He said: "We recognise that there is concern on the usage of Chinese satellites to support our warfighter, and yet [officials recognise that commanders] need support and sometimes we must go [to] the only place that we can get [the service]."