Mr Trump, who attempted to ban TikTok in 2020 while in the White House, said the proposal would give unfair advantages to Facebook owner Meta.
Lawmakers are debating a measure that would force TikTok parent company ByteDance to sell it by 30 September.
President Joe Biden has said he will sign the bill if it passes.
“Without TikTok, you can make Facebook bigger, and I consider Facebook to be an enemy of the people,” Mr Trump told NBC on Monday.
Asked about app’s security, the Republican presidential candidate said “there’s a lot of good and there’s a lot of bad” with the social media platform.
“There are a lot of people on TikTok that love it. There are a lot of young kids on TikTok who will go crazy without it,” Mr Trump added.
The US intelligence community has warned that the Chinese government is using TikTok in attempts to sow doubt about US leadership and undermine democracy.
In an annual report on threats to US security, released on Monday, the Office of the Director of National intelligence wrote that TikTok accounts from the Chinese government’s propaganda arm “reportedly targeted candidates from both political parties during the U.S. midterm election cycle in 2022”.
