Facebook and Twitter have apparently not been invited by the White House to a social media summit hosted by President Donald Trump for a robust conversation on the challenges of the online environment, according to a media report.

The summit, set for Thursday, is to address issues relevant to social media, all the more important as Trump utilises the platforms like no other President before him.

The two prominent social media companies were not extended invitations, CNN quoted sources familiar with the matter as saying.

The sources, who spoke on the condition of anonymity, suggested it was not surprising. They said they feel the summit would amount to a right-wing grievance session and was not aimed at seriously discussing some of the issues facing large technology companies, the report added.

The White House, however, refused to comment, the report said.

A social media summit without representation from the giants like Facebook and Twitter cannot be thought of but President Trump has frequently blasted them for not respecting Republican views on their platforms.

The White House announced the summit in June, describing it as an event to bring together “digital leaders for a robust conversation on the opportunities and challenges of today's online environment”.

The White House has not made public the various companies that will be attending Thursday's event.

In his last meeting with Twitter CEO Jack Dorsey, Trump reportedly questioned the former specifically on why he was losing followers on the microblogging platform.

The White House recently launched a new tool for people to report if they have been wrongly censored, banned or suspended on Facebook and Twitter.

The tool comes in the wake of several Republicans slamming Facebook and Twitter for censoring conservative speech on both the platforms.

A Twitter spokesperson responded to the tool: “We enforce the Twitter Rules impartially for all users, regardless of their background or political affiliation. We are constantly working to improve our systems and will continue to be transparent in our efforts.”

Republican Senator Ted Cruz, the chairman of the Senate judiciary committee's panel that ripped apart Facebook and Twitter over concerns of bias against conservatives in April this year, has often alleged that Silicon Valley giants were biased against conservatives and routinely censor right-wing voices.

Trump in a March tweet accused Facebook, Google and Twitter of being “on the side of the Radical Left Democrats”.

“Social media is totally discriminating against Republican/Conservative voices. Speaking loudly and clearly for the Trump Administration, we won't let that happen,” Trump said last year.

“They are closing down the opinions of many people on the right, while at the same time doing nothing to others,” he added.