London, UK – Julian Assange will find out whether senior judges will overturn a decision not to extradite him to the US when the UK High Court gives its ruling on his case on Friday.

Assange (50) is wanted in the US on allegations of a conspiracy to obtain and disclose national defense information following WikiLeaks's publication of hundreds of thousands of leaked documents relating to the Afghanistan and Iraq wars.

US authorities brought a High Court challenge against a January ruling by then-district judge Vanessa Baraitser that Assange should not be sent to the US, in which she cited a "real and oppressive'' risk of suicide.

The Lord Chief Justice Lord Burnett, sitting with Lord Justice Holroyde, heard arguments from lawyers representing the US and those acting for Assange at a hearing in October.

Supporters of Assange, who observed the hearing via video-link from Belmarsh prison, demonstrated outside the Royal Courts of Justice throughout the hearing.

The court was told that blocking Assange's removal to the US due to his mental health risks was "rewarding fugitives for their flight."

James Lewis QC, for the US, said the district judge based her decision on Assange's "intellectual ability to circumvent suicide preventative measures," which risked becoming a "trump card" for anyone who wanted to oppose their extradition regardless of any resources the other state might have.

He told the court the district judge "entirely based her decision" on the risk Assange would be submitted to special administrative measures (SAMs) and detained at the ADX Florence Supermax jail, if extradited.

However, he said four "binding" diplomatic assurances had been made, including that it would consent to him being transferred to Australia to serve any prison sentence he may be given, which "fundamentally change the factual basis" of her judgment.