For much of the summit, Twitter appeared to be down, an outage the company said it was investigating.
Trump and conservatives have been ramping up their criticism of big tech.
He announced Thursday that he is directing his administration to explore "all regulatory and legislative solutions to protect free speech and the free-speech rights of all Americans".
Alphabet, Facebook and Twitter said they have not received any invitations yet, Reuters reported. Repeatedly, the president also has threatened to investigate or regulate Facebook, Google and Twitter, sparking a series of hearings and similar calls for tough new laws among Republicans on Capitol Hill.
Republican Senator Josh Hawley, who is working on proposed legislation on the issue, took the stage briefly on Thursday to air his complaints.
United Nations inspectors to verify Iran’s claim it has broken nuclear deal
Japan, which has built amiable ties with Iran , has supported the nuclear deal as a way to promote stability in the Middle East . Germany , France, Britain, Russia and China are trying to keep the deal alive amid heightened tension between the USA and Iran .
"I'll tell you a lot of bad things are happening".
"Social media sites may wish to allow many types of speech, but should not be required to stay neutral on hate or religious intolerance". Generic statements about community standards being violated as well as a prominent left-wing culture in some big tech companies don't tend to help matters. He stressed there is "no conservative bias on our platforms". Trump now has 61.8 million followers; as of February, Twitter had 126 million daily active users. Right-wing commentator Ali Alexander, who recently questioned Democratic Sen. Free Speech is a bedrock of American life. The president has suggested, without evidence, that Twitter makes it hard for his supporters to follow him. We'll have more about that when it becomes available. Marsha Blackburn, R-Tenn., who have accused Twitter in the past of limiting the reach of their tweets.
Trump did not invite social media companies to today's summit; he said he'll host a separate event for them in "a week or two" or "over the next month".
Trump tweeted that a big topic will be the "tremendous dishonesty, bias, discrimination and suppression practiced by certain companies".
"Every kind of punctuation mistake they made", he added.
Dozens of pro-Trump online personalities convened in the stately East Room to discuss what they say is censorship on social media platforms, rubbing elbows with several members of Trump's cabinet and his White House team, and his son Donald Trump, Jr.
Among the other conservative organizations participating in the White House meeting were Turning Point USA, a nonprofit; PragerU, short for Prager University, which puts out short videos with a conservative perspective on politics and economics; the Media Research Center; and the Heritage Foundation, a Washington think tank. He leads a House Judiciary subcommittee that has opened a bipartisan probe into the tech giants' market conduct.