Assange had been indicted by the US government for his role in the 2010 leak of around 700,000 classified documents linked to the wars in Iraq and Afghanistan.
His supporters see him as a champion of free speech, while critics point out that publications he has made have endangered US security.
Australian Assange has been imprisoned in the British Belmarsh prison in London since April 2019. He was arrested after spending seven years in the Ecuadorian embassy in London to avoid extradition to Sweden, on suspicion of sex crimes during a visit to Stockholm. The Swedish investigation was closed in 2019.
US President Joe Biden said in April that the US was “considering” a request from Australia to drop the charges against Assange.