The U.S. Federal Communications Commission (FCC) said Wednesday it had begun efforts to revoke authorization for China Unicom (Americas), Pacific Networks and its wholly-owned subsidiary ComNet to provide U.S. telecommunications services.

FCC Commissioner Geoffrey Starks noted many Chinese telecom carriers "also own data centers operating within the United States." He said the FCC currently lacks authority to "address this potential national security threat."

Commenting on the issue, China Unicom said the company's legal subsidiary has been operating in the U.S. for nearly 20 years, and it expects the FCC to conduct a thorough, fair and fact-based review of its behavior.

Meanwhile, the U.S. Department of Commerce said on Wednesday it served subpoenas on multiple Chinese companies that provide information and communications technology and services (ICTS) in the United States. The department didn't specify the targeted companies.

Gina Raimondo, U.S. Secretary of Commerce, said in a statement, "The Biden-Harris administration has been clear that the unrestricted use of un-trusted ICTS poses a national security risk."

Beijing has repeatedly expressed opposition to Washington's threat to cut off China telecom firms from serving the U.S. market. Zhao Lijian, a Chinese Foreign Ministry spokesperson, said last year that China had demanded the U.S. government to abide by market rules, stop stretching the concept of national security and cease politicizing economic issues.