Assange's partner Stella Morris said in a statement: "It will be 1,000 days this Wednesday that Julian Assange has spent in the harshest prison in the U.K. His young children, ages two and four, have no memory of their father outside the highest security prison of the U.K."

"Journalism is not a crime," the Assange Defense Committee tweeted. "#FreeAssange. #DropTheCharges."

The likelihood of Assange's extradition to the United States—where he faces charges of violating the Espionage Act that, if he is convicted, could result in a more than 170-year prison sentence—increased last month after the US won an appeal in the U.K. High Court.

Assange can still appeal to the country's Supreme Court, but there is no guarantee it will consider his case.

Morris and other advocates have previously drawn attention to conditions at Belmarsh, Britain's first supermax prison, where violence, prisoner self-harm, and Covid-19 are rampant.

Assange's numerous maladies—Morris said he suffered a mini-stroke in October, and he also has heart and respiratory ailments—place the 50-year-old at elevated risk of potentially deadly Covid-19 complications, health experts say.