"It will likely be a few days before the (14-day appeal) deadline and the appeal will include new information that we weren't able to bring before the courts previously. Information on how Julian lawyers were spied on, and how there were plots to kidnap and kill Julian from within the CIA," Shipton told Reuters in an interview.

He was referring to a Yahoo News report from September 2021 on alleged U.S. plans to kidnap or assassinate Assange when he was holed up in the Ecuadorean embassy in London. The CIA has declined to comment on the report.

Earlier on Friday, the UK Home Office said Assange's extradition had been approved as British courts had concluded it would not be unjust or an abuse of process.

Shipton said the decision set a dangerous precedent and urged the Biden administration to drop the charges.

"UK government and judiciary at the highest level has found that if you publish evidence of corruption, war crimes and torture in the UK you may be extradited to a third country," Shipton said. "It is now up to President Biden to drop this prosecution and restore faith in the ability of the fourth estate to play their role in functioning democracies."

(Reporting by Kanishka Singh in Washington; Editing by Daniel Wallis)

By Kanishka Singh