WASHINGTON - Major tech companies said on Thursday they would take fresh steps to combat online extremism by removing more violent content and promoting media literacy with young users, as part of a White House summit on fighting hate-fuelled violence.

Platforms like Alphabet's YouTube and Meta Platforms' Facebook have come under fire for years from critics who say the companies have allowed hate speech and violent rhetoric to flourish on their services.

US President Joe Biden called on Americans to combat racism and extremism during a summit at the White House that gathered experts and survivors and included bipartisan local leaders.

YouTube said it would expand its policies to fight violent extremism by removing content that glorifies violent acts, even if the creators of the videos are not related to a terrorist organisation.

The video streaming site will also launch a media literacy campaign to teach younger users how to spot the manipulation tactics that are used to spread misinformation.

Microsoft said it would make a basic and more affordable version of its artificial intelligence and machine learning tools available to schools and smaller organisations in order to help them detect and prevent violence.

Facebook owner Meta announced it would partner with researchers from the Middlebury Institute of International Studies' Centre on Terrorism, Extremism and Counterterrorism.

Last year, lawmakers grilled the chief executives of Alphabet and Facebook, as well as Twitter, on whether their companies bore some responsibility for the events that led to the storming of the US Capitol on Jan 6, 2021. REUTERS