The US has banned Huawei and ZTE equipment from its 5G networks, but the cost of implementing the ban has now risen to $5.6 billion.

According to Network World, Congress had initially set aside $1.9 billion to fund the removal of the Chinese firms’ 5G equipment. At the heart of the issue are national security concerns over the two firms’ connection to Beijing. All Chinese companies are required to cooperate with the government, including its espionage efforts. While this may be a concern in any number of industries, it’s especially a concern in an industry that controls communication and data.

FCC Chairwoman Jessica Rosenworcel has informed Congress the removal of Huawei and ZTE will take at least $5.6 billion, a significant increase over the initial fund.

“Last year Congress created a first-of-its kind program for the FCC to reimburse service providers for their efforts to increase the security of our nations communications networks,” said Chairwoman Rosenworcel. “We’ve received over 181 applications from carriers who have developed plans to remove and replace equipment in their networks that pose a national security threat. While we have more work to do to review these applications, I look forward to working with Congress to ensure that there is enough funding available for this program to advance Congress’s security goals and ensure that the U.S. will continue to lead the way on 5G security.”