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President Donald Trump is all fired up for Thursday's White House social media summit, an event that may not include any representatives from Facebook or Twitter.

On Thursday morning, Trump sent out several tweets previewing the summit, which he said will be a "big and exciting day at the White House for Social Media!"

But not necessarily a day to the liking of Silicon Valley's internet titans. Trump tweeted that the summit will focus on what he called the "tremendous dishonesty, bias, discrimination and suppression practiced by certain companies." He followed that with a warning: "We will not let them get away with it much longer."

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 Fake News Media will also be there, but for a limited period.. — Donald J. Trump (@realDonaldTrump) July 11, 2019

Those companies apparently won't be there to participate in the discussion -- or defend themselves. The White House didn't extended invitations to Facebook and Twitter, anonymous sources familiar with the matter told CNN earlier this week. The White House didn't disclose who's been invited, but the sources said they wouldn't be surprised by the exclusion of the two giants.

A Facebook spokesperson confirmed that the social media giant wasn't invited to the summit. Twitter and the White House declined to comment.

The choice to exclude Twitter and Facebook could stem from Trump's complaints that the social media sites are politically biased against conservatives. Twitter and Facebook have repeatedly denied these accusations, but that hasn't stopped Trump and other lawmakers from raising these concerns.

In March, Trump called the people behind Facebook, Twitter and Google "collusive" and said action should be taken against them. In May, the Trump administration launched a website that allows people to share examples of when they believe they've been suspended, reported or banned on social media because of political bias.

Trump has also accused Twitter of making it hard for people to follow him but has offered no evidence. The president met with Twitter CEO Jack Dorsey in April and complained about losing followers. That month, representatives from Facebook and Twitter also testified at a congressional hearing and denied suppressing conservative speech.

Thursday's summit "will bring together digital leaders for a robust conversation on the opportunities and challenges of today's online environment," the White House said last month when it announced the event.

Trump has leaned heavily on Twitter in both his campaign and presidency. During his Thursday tweetstorm -- in which he described himself as "so great looking and smart, a true Stable Genius!" -- Trump referenced his use of social media: "Would I have become President without Social Media? Yes (probably)!"

The White House will be hosting a very big and very important Social Media Summit today. Would I have become President without Social Media? Yes (probably)! At its conclusion, we will all go to the beautiful Rose Garden for a News Conference on the Census and Citizenship. — Donald J. Trump (@realDonaldTrump) July 11, 2019

CNET's Queenie Wong contributed to this report.

Originally published July 8.

Update, July 11: Adds Thursday's tweets by President Trump.