Urging the U.S. to deny Huawei a role in building the country’s 5G networks, Sen. Marsha Blackburn, R-Tenn., claimed Sunday that China is using Huawei to build a spy network that spans the globe.

“China is building a spy network, they want to win the cyberwar, and what we have to do is continue to say to them, you cannot empower Huawei, which is state-run, regardless of what they say, we know it is state-run, and it is their mechanism for spying,” Blackburn said on Fox’s Sunday Morning Futures show.

The U.S. intelligence community and some members of Congress have long feared that products from Huawei and Chinese firm ZTE Corporation could be leveraged by the Chinese government to spy on American targets.

Amid escalating trade war tensions with China and a lengthy dispute over Huawei Technologies over espionage allegations, President Trump declared a national emergency that bans U.S. telecommunications companies from using equipment from foreign firms that could threaten national security.

Previously, the Defense Department instructed its procurers and contractors to stop buying software that may have Chinese or Russian connections to help defend these institutions against a possible cyberattack.

In January Huawei fired Director of Sales Weijing Wang, who had been arrested in Poland on charges of spying for China. The company said he was fired for bringing disrespect to Huawei. By the end of that month U.S. federal prosecutors had filed criminal charges against Huawei, alleging the company stole intellectual property from T-Mobile and violated U.S. sanction orders.

In May, Europe’s Vodafone said it found backdoors in the software contained in Huawei home routers and optical service nodes. Such backdoors could allow Huawei to gain access to Vodafone’s fixed-line network in Italy, according to Vodafone security documents dating from 2009 to 2011.

At the time, Sen. Mark Warner, D-Va., called for the Trump administration to step up efforts to protect 5G as China takes the lead in its rollout and to bolster U.S. infrastructure.  

“It should also be noted that we have yet to see a compelling strategy from this Administration on 5G, including how the Administration intends to work cooperatively with our allies and like-minded nations to ensure that international standards set for 5G reflect Western values and standards for security and privacy,” Warner said. “Nor do we have a stated plan for replacing this equipment from existing commercial networks – a potentially multi-billion dollar effort that, if done ineptly, could have a major impact on broadband access in rural areas.”

The senator called for “a coherent coordinated and global approach,” which he said “is critically needed as nations and telecom providers move to implement 5G.”

On the Fox show, Blackburn said, “We do not need to let Huawei get into building out these 5G networks, not for us and not for any of our allies because of the dangers there.”