WASHINGTON, May 2 (Reuters) - The Federal Communications Commission (FCC) said on Thursday nearly 40% of U.S. telecom companies getting federal support need additional government funding to remove equipment made by Chinese telecoms firms Huawei and ZTE from American wireless networks to address security risks.

The FCC said removing the equipment is estimated to cost $4.98 billion but Congress has only approved $1.9 billion for the "rip and replace" program.

FCC Chair Jessica Rosenworcel on Thursday called on Congress for urgent additional funding, warning some carriers in the reimbursement program have told the FCC recently "that they foresee significant consequences that could result from the lack of full funding, including having to shut down their networks."

The White House in October sought another $3.1 billion to further fund removal of equipment made by Chinese telecoms giants but Congress has not acted.

In 2019, Congress told the FCC to require U.S. telecoms carriers that receive federal subsidies to purge their networks of Chinese telecoms equipment.

Under the law, the FCC is first allocating funding to applicants with two million or fewer customers and they are receiving just 39.5% of replacement costs.

After getting initial partial funding, telecoms companies face deadlines to remove, replace, and dispose all Huawei and ZTE communications equipment and services ranging from May 29, to Feb. 4, 2025, the FCC said.

The FCC said because telecom providers in the program "serve many rural and remote areas of the country where they may be the only mobile broadband service provider, a shutdown of all or part of their networks could eliminate the only provider in some regions."

Rosenworcel added that a failure by carriers to "fully remove, replace, and dispose of covered equipment and services would raise national security concerns by leaving insecure equipment and services in our networks." (Reporting by David Shepardson Editing by Alexandra Hudson)