The president said, as part of a morning tweet storm on a smorgasbord of topics, "a big subject today at the White House Social Media Summit will be the tremendous dishonesty, bias, discrimination and suppression practiced by certain companies."
"We will not let them get away with it much longer," the president added, threatening uninvited social media giants.
According to the White House, the Thursday event "will bring together digital leaders for a robust conversation on the opportunities and challenges of today's online environment." The president has complained about bias against conservatives online and even his own social media accounts.
"Facebook was against me. They were all against me. Twitter was against me," Trump said in an interview with Tucker Carlson on Fox News. "There are a lot of people that want us to take action against Facebook and against Twitter."
"But they don't treat me right. And I know for a fact, I mean, a lot of people try and follow me, and it's very hard," the president alleged. "I have so many people coming up that they say, 'Sir, it's so hard. They make it hard to follow.' What they're doing is wrong and possibly illegal. And a lot of things are being looked at right now."
In a statement, White House deputy press secretary Judd Deere said earlier this year the White House launched a tool for Americans to "share how they have been affected by bias online."
"After receiving thousands of responses, the President wants to engage directly with these digital leaders in a discussion on the power of social media," Deere said.
The White House would not confirm the guest list for Thursday afternoon's event, but ABC News has confirmed it includes Trump's 2020 campaign director Brad Parscale, Rep. Matt Gaetz, R-Fla., Charlie Kirk, president of Turning Point USA, a conservative youth organization, executives from the conservative think tank Heritage Foundation and James O'Keefe, founder of Project Vertias, which is known to secretly film journalists and executives in "gotcha" scenarios to try and reveal bias.
Right-wing social media accounts like @CarpeDunktum, which created a viral meme, retweeted by Trump, of Democrats crying during the State of the Union -- later deleted by Twitter -- and Bill Mitchell, who has promoted conspiracy theories like QAnon on his Twitter account, also will be in attendance.
The only social media platform invited by the White House is Minds.com, a cryptocurrency site built in protest of Facebook, a representative from Pulp PR, which represents Minds.com, confirmed to ABC News. Minds.com's invitation was first reported by Vice, which said the site has been known to host neo-Nazi groups due to its lax moderation.
"There are a lot of concerns about how these tech companies are acting," Kirk of Turning Point USA told ABC News. "In particular, the suppression of certain ideas, and conservative ideas, and how they're being labeled."
"At a time when social media is having a transformative effect on much of American culture, it's a welcome opportunity to talk with other digital leaders at the White House," said Robert Bluey, vice president of communications and executive editor of The Daily Signal. "Think tanks and publishers are wrestling with important questions about social media. While there are some pushing for heavy-handed government regulation, there's evidence the market is working and social media companies are responding."
The event comes the same week that a federal appeals court ruled that the president can't block Twitter users from his account. The president has threatened to take legal action against social media and tech giants, although he hasn't been specific.
"The First Amendment does not permit a public official who utilizes a social media account for all manner of official purposes to exclude persons from an otherwise‐open online dialogue because they expressed views with which the official disagrees," the decision said.
A spokeswoman for the Department of Justice, Kelly Laco, said they were "disappointed" with the court's decision: "As we argued, President Trump's decision to block users from his personal twitter account does not violate the First Amendment."
This spring, the president invited Twitter CEO Jack Dorsey to the Oval Office to reportedly discuss perceived social media biases, an issues he claimed affects his adding of Twitter followers.
"We enforce the Twitter Rules impartially for all users, regardless of their background or political affiliation," a Twitter spokesperson said. "We are constantly working to improve our systems and will continue to be transparent in our efforts."
Trump, who frequently slams social media, uses Twitter as a personal sounding board and to announce potential policy decisions.
He has more than 61 million followers.