Senate mulls TikTok ban amid US national security concerns

Senators from both sides of the aisle warned Wednesday that TikTok endangers millions of users in the United States -- as Congress continues to weigh how to protect U.S. national security amid growing concern that the Chinese social media platform is a propaganda tool that could have a lasting impact on the coming U.S. election.

"TikTok is a gun aimed at Americans' heads," Sen. Richard Blumenthal, D-Conn., warned following a classified briefing in the Capitol. "The Chinese communists are weaponizing information that they are constantly surreptitiously collecting from 170 million Americans and potentially aiming that information using it through algorithms at the core of American democracy."

Days after the House overwhelmingly passed bipartisan legislation to effectively ban TikTok in the United States if its Chinese owners do not sell the app, senior officials from the FBI, Justice Department and the Office of the Director of Intelligence held a classified briefing for members from the Senate Intelligence and Commerce committees.

"TikTok is a grave national security threat to Americans. It's a threat to your privacy and the security of your data on your phone if you use Tik Tok. It's also a threat for Chinese Communist propaganda," Sen. Tom Cotton, R-Ark., said. "Tik Tok and ByteDance and Chinese leaders go to great lengths to try to conceal what they're doing. But it's clear right there in the terms and conditions what they can do. And it's clear from two weeks ago, how TikTok is used to try to influence American politics."

Senators leaving the closed-door briefing also called for the relevant intelligence to be declassified.

"I will say very emphatically, the American people need and deserve to hear what we've just been told. Because they would be deeply frightened," Blumenthal said. "The American people should be told everything that we heard, there is absolutely no reason to keep it secret. There are no sources or methods that may be endangered. Its analysis by our people about what the Chinese communists are doing. They know what they're doing. We don't need to keep secret from them what they know they are doing right now. Only the American people don't know and they deserve to hear."

Senate Commerce Committee Chair Maria Cantwell, a Washington State Democrat, refused to put a timeline on advancing legislation through the Senate, though her committee would be expected to take the next step by holding a markup to make potential amendments to the House-passed measure.

"We're gonna resolve this one way or another for sure, because it's an important issue," Cantwell said. "This is the information age, we need some new tools."

Sen. Ted Cruz, the ranking Republican on the Commerce Committee, urged Cantwell to hold a mark-up on the House bill "expeditiously."

"The content on TikTok in China is pushing things like math and science and education and hard work and discipline. And here in the United States, the Chinese Communist Party is pushing things to our kids like self-harm and suicide," Cruz, R-Texas, said. "They're studying math and science and they're trying to get our kids to chew on Tide pods. That is deeply concerning."

While there were some early indications that the bill could die in the Senate, it now appears that there is momentum building to tweak the House-passed bill later this spring.

As a full-press lobbying effort continues on Capitol Hill, senators advocated for legislation that compels ByteDance, TikTok's parent company, to divest from Chinese ownership -- whether it's an American buyer or one from a country that is not hostile to the United States, such as Iran, North Korea, China and Russia.

"U.S. companies should buy TikTok and I think that we should pass the legislation promptly that will force ByteDance to sell TikTok to a company or a big group of investors or some entity that is not under the thumb of the Chinese Communist Party," Cotton said.

"It doesn't have to be an American," Sen. Marco Rubio, the top Republican on the Senate Intelligence Committee, added. "In my view, it has to be a company that is not subject to the national security laws of China."

Even though the social media platform has faced growing scrutiny from some government officials over fears that user data could fall into the possession of the Chinese government -- and that the app could be weaponized by China to spread misinformation --cybersecurity experts have told ABC News there is little evidence that TikTok has shared U.S. user data with the Chinese government or that the Chinese government has asked the app to do so.

TikTok denies security or privacy risks and says a firewall has been established to prevent that.

South Dakota Republican Sen. Mike Rounds pointed out the obvious reality that nothing will happen this week or even within the next three weeks, given the looming congressional recess that begins at the end of the week -- pending an averted government shutdown this weekend.

Congress returns from a two-week spring break on April 8.

ABC News' Max Zahn contributed to this report.