Assange is awaiting a potentially final appeal hearing, scheduled at the High Court in London from February 20-21, against a US order to extradite him on espionage charges.
"His health is in decline, mentally and physically. His life is at risk every single day he stays in prison, and if he’s extradited, he will die," The Independent quoted Stella Assange as telling journalists.
She pointed out the seriousness of the situation and added that Julian Assange could be on a plane to the US "within days."
Stella added that her husband "should never have been put in prison in the first place" and called the case a "politically motivated" one, saying it violates the UK-US extradition treaty which prohibits extradition for political reasons.
She also said the "bogus extradition request" would have been thrown out by London if it was made by any country other than the US.
If the High Court in London rejects Assange's appeal, he would apply to the European Court of Human Rights for an order under Rule 39 to stop the extradition while it considers his case, she said.
Assange, an Australian citizen, was transferred to London's high-security Belmarsh prison in April 2019 on bail breach charges. In the US, he faces prosecution under the Espionage Act for obtaining classified information and publishing it in the public domain. If convicted, the WikiLeaks founder could face 175 years in prison. Assange lost his previous appeal at the UK High Court last June.
WikiLeaks was founded by Assange in 2006 but rose to prominence in 2010 when it began publishing large-scale leaks of classified government information, including from the US.