If you are shopping for a new smartphone, stay away from Huawei phones, warn U.S. national security agency chiefs.

Six top U.S. intelligence chiefs told the Senate Intelligence Committee on Tuesday that they would not recommend phones made by China-based Huawei as they may pose a cybersecurity risk for private U.S. citizens. The chiefs — including the heads of CIA, FBI, NSA and the director of national intelligence — extended their concerns to the telecom company ZTE for the same reason.

“We’re deeply concerned about the risks of allowing any company or entity that is beholden to foreign governments that don’t share our values to gain positions of power inside our telecommunications networks,” said FBI Director Chris Wray, according to CNBC.

U.S. government officials have long been wary of the relationship between Huawei — which has been trying to break into the U.S. market in recent years as a new smartphone alternative to Apple — and the Chinese government.

In January, U.S. Rep. Mike Conaway, R-Texas, proposed a bill to ban all government agencies from purchasing equipment or services from Huawei and ZTE, worried that any usage of Huawei and ZTE equipment “would be inviting Chinese surveillance into all aspects of our lives.”

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However, a 2012 White House-ordered review of security risks found no clear evidence that Huawei had spied for China, according to Reuters. There has been no similar research conducted in recent years but U.S. intelligence agencies have repeatedly claimed Huawei poses a security risk.

“It provides the capacity to maliciously modify or steal information,” Wray said. “And it provides the capacity to conduct undetected espionage.”

In recent months, AT&T and Verizon both pulled out of partnerships with Huawei after pressure from the U.S. government. The government also pressured Verizon to drop its partnerships with Huawei in creating standards for a 5G network.

Huawei still plans to make its phones — including the new 10 Mate Pro model — available in the United States through Amazon, Best Buy and other online retailers.

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“Huawei is aware of a range of US government activities seemingly aimed at inhibiting Huawei’s business in the U.S. market,” said the company in a statement to Engadget. “Huawei is trusted by governments and customers in 170 countries worldwide and poses no greater cybersecurity risk than any ICT vendor, sharing as we do common global supply chains and production capabilities.”