Facebook will suspend Donald Trump’s account for the remainder of his term in office, a dramatic censure of the US president following years of resistance to criticisms that social media platforms helped stoke the violent unrest that erupted this week in the US Capitol.

Mark Zuckerberg, chief executive of the world’s largest social media platform, wrote in a blog post on Thursday that the president would be locked out of posting on his Facebook and Instagram accounts “indefinitely and for at least the next two weeks until the peaceful transition of power is complete”.

Mr Zuckerberg said Mr Trump had wielded the platform “to incite violent insurrection against a democratically elected government”, adding: “we believe the risks of allowing the president to continue to use our service during this period are simply too great.”

The move, Facebook’s strongest rebuke of a global leader to date, extends a temporary 24-hour ban announced by the platform on Wednesday, and snatches a vital mouthpiece from the president in the lead-up to the inauguration of Democratic president-elect Joe Biden on January 20.

It is a remarkable volte-face for Mr Zuckerberg, who has long argued that private companies should not be the “arbiter of speech” and has often allowed rule-breaching posts by politicians to remain on its platform, deeming it to be “in the public interest”.

Social media platforms have faced a torrent of criticism over the past 24 hours for failing to stem the spread of pro-Trump conspiracy theories, hate speech and domestic extremism online despite repeated warnings from experts.

The posts that triggered Facebook’s dramatic action included a video in which Mr Trump told the Washington protesters to “go home” — but offered them sympathy, declaring his “love” for them and reiterating claims that the election was “stolen” and “fraudulent”.

In another post on Wednesday, Mr Trump described the unprecedented storming in the Capitol — during which four people died — as the result of an “election victory” being “viciously stripped away from great patriots”.

It was not clear whether Twitter will follow Facebook lead. The company was the first to block his account on Wednesday for 12 hours for “repeated and severe violations” of its civic integrity policies, which ban misleading posts designed to interfere in the election process.

That suspension was lifted early on Thursday, and the president later tweeted a video in which he conceded defeat and did not explicitly reiterate his claims of election fraud.

Twitter said the company was “continuing to evaluate the situation in real time, including examining activity on the ground and statements made off Twitter”. It has said future violations of its rules by the account would result in its “permanent suspension”.

YouTube also took down Mr Trump’s video, citing new policies banning claims of widespread election fraud, but his account remains intact.

Mr Trump and a loyal group of rightwing online influencers have courted conspiracy groups such as QAnon and routinely amplified misinformation on social media regarding coronavirus and the election process, pushing the false narrative that the poll was illegally “stolen” by Democrats.

During the presidential campaign, the platforms started to apply fact-checking labels to some of Mr Trump’s posts. In response, he threatened to overhaul Section 230 regulations that protect the platforms from liability for user-generated content, citing bias against conservatives.

Trump supporters complained that the president was being “censored”, with one far-right podcaster Matt Couch writing on Twitter that “Big Tech must be stopped!”

By contrast, leftwing politicians and experts responded to the suspensions with scepticism, deeming them an act of political manoeuvring as Mr Biden’s electoral college victory was certified on Wednesday.

“It has not escaped my attention that the day social media companies decided there actually IS more they could do to police Trump’s destructive behaviour was the same day they learned Democrats would chair all the congressional committees that oversee them,” Jennifer Palmieri, former White House communications director under Hillary Clinton, wrote on Twitter.

Some argued that the actions did not go far enough to counter the platform’s perceived role in stoking unrest, and urged a complete social media ban for Mr Trump.

Democratic senator Mark Warner, the incoming chair of the Senate intelligence committee, said “these isolated actions are both too late and not nearly enough”.

He added: “These platforms have served as core organising infrastructure for violent, far-right groups and militia movements for several years now — helping them to recruit, organise, co-ordinate and in many cases (particularly with respect to YouTube) generate profits from their violent, extremist content.”

Alex Stamos, Facebook’s former chief security officer and a professor at Stanford University, characterised the platforms’ response to Mr Trump’s posts as floundering, arguing for more transparent policymaking and enforcement in tackling emergencies in real time.

“Clear, publicly discussed redlines would have allowed both platforms to act in minutes, not hours,” he said.

The Real Facebook Oversight Board, a collective of Facebook critics from academia, business and politics, said the mob assault on the Capitol “showed that Facebook is not fit to police itself”.

Inside Facebook, some staff echoed outside criticism that the company only acts in response to PR crises.

“It’s unfortunate Facebook can never be a leader and is always a follower,” one Facebook employee told the Financial Times. “They are always responding to pressure and not proactively.”

Other businesses also moved to limit promotion of the president and his messaging. Streaming platform Twitch disabled his account, while Shopify said it had deactivated two stores on the ecommerce platform that were affiliated with Mr Trump — cutting off merchandise sales on the president’s official website — citing policies promoting users that “condone violence to further a cause”.

Additional reporting by Dave Lee in San Francisco