U.S. telecommunications and Internet providers can no longer use federal subsidies to buy network equipment from Chinese suppliers Huawei or ZTE and might be forced to rip out existing gear at a cost of more than $2 billion, the Federal Communications Commission ruled Friday.

The five FCC commissioners unanimously concluded that the national security risks of using the Chinese equipment are too great and backed an order barring the use of $8.5 billion in annual subsidies to buy the gear.

The commissioners also voted to consider requiring subsidy recipients to remove and replace existing Chinese gear in their networks.

Use of Huawei and ZTE gear is not widespread in U.S. phone and Internet networks. It is largely limited to small, rural telecom providers that have purchased the equipment over the years because it is cheaper. Those rural companies rely on federal subsidies to make ends meet.

Huawei denounced the order and called on the FCC to “refrain from finalizing it.”

In a statement, it called the order illegal, saying it singles out Huawei as a national security threat without presenting any evidence, violating “bedrock principles of due process.” The order, Huawei said, “is based on nothing more than irrational speculation and innuendo” and reiterated Huawei’s oft-stated willingness to work with the FCC and “other U.S. agencies” to develop ways to protect communications security.

If the FCC does ultimately force rural carriers to replace Chinese gear, it plans to establish a reimbursement program to help cover the cost, FCC Chairman Ajit Pai said during a public meeting Friday at the agency’s headquarters.

Commissioner Geoffrey, citing “information available today,” said the cost of removing and replacing the equipment in roughly two dozen rural networks could be $2 billion or more.

The FCC vote reflects months-long concern among U.S. officials that China’s ruling Communist Party could tap into Chinese telecom gear to spy on or disrupt U.S. communications — concerns that Beijing and the Chinese companies have rejected.

Chinese gear “could suck up data, disrupt service or launch denial-of-service attacks,” Commissioner Jessica Rosenworcel said before supporting the measure. “I have only one complaint with this effort — that it took us so long to get here.”