The Biden administration is threatening a possible ban on TikTok in the United States if its Chinese owners refuse to sell their stakes in the video-sharing app, a source close to the company told NBC News on Thursday.

The source, however, cautioned that the company did not view the administration’s move as a final order.

The request of the administration first reported by the Wall Street Journal, signals a significant shift in the US stance toward Beijing-based ByteDance Ltd., which owns the popular video-sharing app.

The White House and the Treasury Department declined to comment to NBC News.

In a statement, a TikTok spokesperson said: “If the goal is to protect national security, divestment does not solve the problem: a change of ownership would not impose new restrictions on data flows or access. National security concerns are best addressed with transparent, US-based protection of US user data and systems, with robust monitoring, investigation, and third-party verification, that we are already implementing”.

Any divestment by ByteDance Ltd. would have to be approved by the Chinese government. A Foreign Ministry spokesman said Thursday that the United States did not provide any evidence that TikTok poses a threat to its national security.

“The US side must stop spreading false information on the issue of data security, stop unreasonably suppressing the companies in question, and provide an open, fair, equitable, and non-discriminatory business environment for companies from all countries. invest and operate in the US,” the spokesman, Wang Wenbin, said at a regular press conference.

Brooke Oberwetter, a spokeswoman for TikTok, told NBC News last week that the Biden administration already has the power to oversee the app through the Committee on Foreign Investment in the United States.

News of the administration’s lawsuit comes a week after the White House endorsed a bipartisan bill in Congress that would allow the federal government to regulate and even ban foreign-produced technology, including TikTok. TikTok CEO Shou Zi Chew will testify before Congress next week.

In late December, Biden signed into law legislation banning TikTok on government devices.

Republicans have repeatedly criticized the Biden administration’s handling of security concerns around TikTok. Those criticisms grew stronger last month when some Republican critics tried to link the app to the alleged Chinese spy balloon that traversed the United States.

Opponents of a potential TikTok ban have countered that banning the app on US phones is not a comprehensive solution to data security issues.

During the last year of his presidency, Donald Trump tried to ban TikTok downloads, but the Commerce Department eventually backed down from an order forcing it to shut down, following a lawsuit.

Jace Zhang, jennifer jett and summer conception contributed.