SAN FRANCISCO: Microsoft on Friday (July 18) said it will stop using China-based engineers to provide technical assistance to the US military after a report in investigative journalism outlet ProPublica sparked questions from a US senator and prompted Defence Secretary Pete Hegseth to order a two-week review of Pentagon cloud deals.

The report detailed Microsoft's use of Chinese engineers to work on US military cloud computing systems under the supervision of US "digital escorts" hired through subcontractors who have security clearances but often lacked the technical skills to assess whether the work of the Chinese engineers posed a cybersecurity threat.

Microsoft, a major contractor to the US government, has had its systems breached by Chinese and Russian hackers.

It told ProPublica it disclosed its practices to the US government during an authorisation process.

On Friday, Microsoft spokesperson Frank Shaw said on social media website X the company changed how it supports US government customers "in response to concerns raised earlier this week ... to assure that no China-based engineering teams are providing technical assistance" for services used by the Pentagon.

Earlier on Friday, Senator Tom Cotton, an Arkansas Republican who chairs the chamber's intelligence committee and also serves on its armed services committee, sent a letter to Defense Secretary Pete Hegseth about Microsoft's reported practices.

Cotton asked the US military for a list of contractors that use Chinese personnel and more information on how US "digital escorts" are trained to detect suspicious activity.

"The US government recognises that China's cyber capabilities pose one of the most aggressive and dangerous threats to the United States, as evidenced by infiltration of our critical infrastructure, telecommunications networks, and supply chains," Cotton wrote in the letter.

The US military "must guard against all potential threats within its supply chain, including those from subcontractors," he wrote.

In a video posted on X on Friday, Hegseth said he was initiating a two-week review to ensure China-based engineers were not working on any other cloud services contracts across the Defence Department.

"I'm announcing that China will no longer have any involvement whatsoever in our cloud services, effective immediately," Hegseth said in the video.

"We will continue to monitor and counter all threats to our military infrastructure and online networks." - Reuters