Christopher Wray, director of the Federal Bureau of Investigation, is "extremely concerned" about TikTok's operations in the U.S., he told lawmakers on Tuesday.

Wray warned lawmakers that the app's recommendation algorithm, which chooses which videos users would watch next, "could be used for influence operations if they so choose," and that China's government might use it to manipulate the data or software of millions of users.

"Under Chinese law, Chinese companies are required to essentially -- and I'm going to shorthand here -- basically do whatever the Chinese government wants them to do in terms of sharing information or serving as a tool of the Chinese government," Wray told the House Homeland Security Committee. "That's plenty of reason by itself to be extremely concerned."

Wray's comments follow those of other government officials and members of Congress who have expressed grave doubts about the Chinese-owned video platform's capacity to protect U.S. user data.

TikTok has stated that it does not store U.S. user data in China, where the government has the authority to compel companies to hand over internal information.

The popular video-streaming app, which has millions of users in the U.S., has become embroiled in a long-running national security dispute. At the same time, it's become critical for reaching out to young voters, who are increasingly avoiding social networks like Facebook and Twitter.

A proposal to allow TikTok to continue operating in the U.S. under the control of its Chinese parent company ByteDance Ltd. is being considered by the Biden administration. As part of the agreement, Oracle Corp. would manage servers that would route traffic from U.S. users while also reviewing the app's algorithms.

"As Director Wray specified in his remarks, the FBI's input is being considered as part of our ongoing negotiations with the U.S. Government," a TikTok spokesperson said in a statement. "While we can't comment on the specifics of those confidential discussions, we are confident that we are on a path to fully satisfy all reasonable U.S. national security concerns."

Any facts about TikTok's actions, according to Wray, would have to be shared in a classified briefing. However, he assured lawmakers that "it is certainly on our radar, and we share your concerns."

Wray stated that the FBI's foreign investment branch is collaborating with the Department of Justice to find a viable solution as part of the foreign investment review process. He stated that the FBI's advice "would be taken into account in any agreements made to address the issue."