In a statement, the US Treasury said Yin Kecheng "was associated with the recent compromise of the Department of the Treasury's Departmental Offices network."

Yin Kecheng, it added, had been a "cyber actor" for more than a decade and was affiliated with China's Ministry of State Security (MSS).

The Treasury move comes just three days before US President Joe Biden makes way for President-elect Donald Trump, and it follows an earlier US determination that a Chinese state-sponsored actor had been behind the breach.

"The Treasury Department will continue to use its authorities to hold accountable malicious cyber actors who target the American people, our companies, and the United States government, including those who have targeted the Treasury Department specifically," deputy Treasury Secretary Wally Adeyemo said.

Separately, in an opinion piece for Bloomberg News, Adeyemo called Yin Kecheng a "state-backed actor" and accused him of hacking into the Treasury's unclassified systems.

Earlier this week, several US media outlets reported that Treasury Secretary Janet Yellen, Adeyemo and another senior Treasury official were among those targeted by the hack.

A Treasury spokesperson declined to comment on the reports.

In addition to the sanctions against Yin Kecheng, the Treasury Department announced sanctions against Sichuan Juxinhe Network Technology Co., "a Sichuan-based cyber-security company with direct involvement in the Salt Typhoon cyber group."

The Salt Typhoon group "recently compromised the network infrastructure of multiple major US telecommunication and internet service provider companies," the Treasury statement said.

The group reportedly used that access to target senior US politicians including Donald Trump, Vice President-elect J.D. Vance and people close to the outgoing vice president, Kamala Harris.