"As far as TikTok is concerned, we're banning them from the United States," Trump said to reporters while aboard Air Force One.
Trump said he could use emergency economic powers or an executive order. It was not immediately clear what such an order would look like.
"Well, I have that authority," he said.
Earlier on Friday, people working on the issue within the Trump administration expected the President to sign an order to force ByteDance, the Chinese company that owns the social media platform, to sell the US operations of TikTok, according to a person familiar with the matter.
The move was aimed at resolving policymakers' concerns
that the foreign-owned TikTok may be a national security risk.
The US government is conducting a national security review of TikTok and is preparing to make a policy recommendation to Trump, Treasury Secretary Steven Mnuchin told reporters this week at the White House.
ByteDance has been considering changes to its corporate structure
and had reportedly already been looking into the possibility of selling a majority stake in TikTok.
) is in talks to acquire TikTok, according to the New York Times
, citing a person with knowledge of the discussions. Microsoft declined to comment to CNN Business. Trump firmly rejected the idea of a potential spin off deal satisfying national security concerns.
Critics of TikTok worry that the data it collects on its US users could end up in the hands of the Chinese government, though TikTok has said it stores its data outside of China and that it would resist any attempts by Beijing to seize the information.
Cybersecurity experts have said TikTok's potential risk to national security is largely theoretical
and that there is no evidence to suggest that TikTok's user data has been compromised by Chinese intelligence.