Former US President Donald Trump has criticised a congressional bill to force TikTok's parent company to sell the app or see it banned in the US.
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.
I think Facebook has been very bad for our country, especially when it comes to elections," Mr Trump added.
Shares in Facebook's parent company Meta fell sharply after the attack, dropping more than 4% on a day when stocks were generally flat. Shares in its smaller social media rival, Snap, were also lower.
Mr Trump's comments offered a preview of the heightened political scrutiny social media firms are likely to face this year as the presidential election in November draws near.
TikTok last faced a serious campaign for a sale or ban in 2020, the last time Mr Trump and Mr Biden were vying for the White House.
At the time, American officials said they feared that data from ByteDance - a Chinese tech giant - could fall into the hands of the Chinese government.
TikTok executives deny sharing any data with Beijing, and maintain they would refuse to do so if asked.
In 2020, Mr Trump signed a presidential executive order that directed ByteDance to sell off TikTok within 90 days, but it was stymied by legal challenges.
Meta removed his accounts following the US Capitol riot in 2021.
Club for Growth, a conservative lobbying group that is close with Mr Trump, has taken a strong stand against the proposed TikTok ban.
Last week Mr Trump met a major donor to the group, billionaire hedge fund manager Jeff Yass.
Kellyanne Conway, who was one of Mr Trump's top aides in the White House, has in recent months been lobbying for TikTok in Congress on behalf of the Club for Growth.
Meanwhile, the Justice Department, FBI and other national security officials plan on Tuesday to brief all members of the House of Representatives on TikTok, one of the most popular apps in the US, especially among younger people, according to the BBC's media partner CBS News.
The bipartisan bill passed a congressional committee last week by a vote of 50-0.
The Senate must also vote to approve the bill before it could be signed into law.
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".
Mr Trump said in his NBC interview that he agreed with those who see TikTok as a national security threat, but argued that Facebook was also a threat to the US government.