A US judge has dismissed former President Donald Trump's lawsuit against Twitter that challenged his suspension from the social media platform.

In a written ruling, US District Judge James Donato in San Francisco rejected Mr Trump's argument that Twitter violated his right to freedom of speech guaranteed by the First Amendment of the US Constitution.

Twitter and other social media platforms banned Mr Trump from their services after a mob of his supporters attacked the US Capitol in a deadly riot on 6 January 2021.

That assault followed a speech by Mr Trump in which he reiterated false claims that his election loss in November was because of widespread fraud, an assertion rejected by multiple courts and state election officials.

Mr Trump's lawyers alleged in a court filing last year that Twitter "exercises a degree of power and control over political discourse in this country that is immeasurable, historically unprecedented, and profoundly dangerous to open democratic debate."

At the time of removing Mr Trump's account permanently, Twitter said his tweets had violated the platform's policy barring "glorification of violence."

The company said then that Mr Trump's tweets that led to his removal were "highly likely" to encourage people to replicate what happened in the Capitol riots.

Before he was blocked, Mr Trump had more than 88 million followers on Twitter and used it as his social media megaphone.