The Chinese government may be using TikTok to control the data of millions of American users, FBI Director Christopher Wray told a US Senate hearing on Wednesday, saying the Chinese-owned video app raised security concerns, Reuters reported.

Wray told a Senate Intelligence Committee hearing on US global security threats that the Chinese government could also use TikTok to control software on millions of devices and create narratives to divide Americans over Taiwan or other issues.

“Yes, and I’d like to stress, especially on that last point, that we’re not sure we’d see a lot of outward signs of that if that were to happen,” Wray said of concerns that China might be feeding misinformation to users.

“This is a tool that is ultimately under the control of the Chinese government, and that, in my view, is a national security concern,” Ray said.

The White House backed legislation introduced by a dozen senators on Tuesday that would give President Joe Biden’s administration new powers to ban TikTok and other foreign technologies if they pose a threat to national security.

That support has fueled efforts by several lawmakers to ban the popular app, which is owned by Chinese company ByteDance and is used by more than 100 million Americans.

Other top US intelligence officials, including Director of National Intelligence Avril Haynes, CIA Director William Burns and National Security Agency Director Paul Nakasone, agreed at the hearing that TikTok posed a threat to US national security.

Nakasone raised concerns during Senate testimony Tuesday about TikTok’s data collection and its potential to facilitate large-scale influence operations.