The US government on Wednesday launched an appeal against a British judge's decision to block the extradition of WikiLeaks founder Julian Assange.

Washington is seeking to bring Assange to the US to face trial for publishing military secrets.

Why is the Assange case back in court now?

UK District Judge Vanessa Baraitser ruled against extradition in January, after determining that it was unclear that the US would be able to ensure Assange's safety in its prison system, which she said was known for "harsh conditions."

She rejected US experts' testimony that Assange would be protected from self-harm, noting that others such as disgraced US financier Jeffrey Epstein had managed to kill themselves while in custody.

Washington expressed "extreme disappointment" with Baraitser's decision, saying the judge "didn't appreciate the weight" of expert evidence that Assange was not at risk of suicide. 

The US argued Baraitser was "misled" by Assange's psychiatric expert Michael Kopelman, who they claim concealed information such as that his client had fathered children while holed up in the Ecuadorian embassy in London.

Washington is now asking the UK's High Court to overturn the ruling during the new two-day hearing.

US says Assange would not face supermax jail

The US argued on Wednesday that Assange would not be held at a federal supermax prison.

Lawyer James Lewis, representing the US government, said Asssange would not be held either before or after his trial at the notorious prison.

He also said Assange "will receive any such clinical and psychological treatment as is recommended" and that he would eventually be able to apply for a prisoner transfer to his native Australia.

"There has never been a previous breach of an assurance," Lewis argued.

But Assange's team said those assurances could not entirely rule out the chance of him being detained at the facility, at a "comparable" federal prison or a state-level supermax jail. They also argued that Australia had not agreed to take him, and even if they did, the extradition process could take a decade, during which time he would be held in solitary confinement.

The US also argued that Assange did not meet the threshold of being so ill that he cannot resist harming himself.

Lewis said Assange did "not even come close to having an illness of this degree."

Assange's lawyers responded, accusing US lawyers of seeking to "minimize the severity of Mr Assange's mental disorder and suicide risk."

What does the US accuse Assange of?

The WIkiLeaks founder is wanted in the US on charges relating to the 2010 release by WikiLeaks of 500,000 secret files detailing information about the Afghanistan and Iraq military campaigns.

Assange was indicted for violating the US espionage act and for hacking. That was based on the alleged assistance he provided former military intelligence officer Chelsea Manning, who obtained the documents from secure military computer systems.

He faces a maximum sentence of 175 years in jail for the alleged crimes.

The 50-year-old Australian national had spent seven years inside the Ecuadorian embassy in London to avoid extradition to Sweden, where he faced allegations of sexual assault.

Ecuador had granted him citizenship to bolster his stay at the embassy but after several years, relations with Ecuadorian authorities became strained. 

Even though the Swedish charges were dropped, he was ultimately removed from the embassy and arrested in 2019 in the UK on charges of skipping bail.

Although his extradition has been blocked, he has been denied bail pending the outcome of the US appeal, after being considered a flight risk.

Rights groups on the Assange case

Journalism organizations and human rights groups have called on US authorities to drop the charges against Assange and urged British authorities to release him immediately.

Wikileaks supporters say claims the CIA spied on Assange during his stay at the embassy suggest he will not receive a fair trial.

Amnesty International highlighted an investigation by Yahoo News revealing that US security services considered kidnapping or killing Assange when he was living in the Ecuadorian embassy in London.

Secretary-General Agnes Callamard said the report had "cast even more doubt on the reliability of US promises and further expose the political motivation behind this case." 

"It is a damning indictment that nearly 20 years on, virtually no one responsible for alleged US war crimes committed in the course of the Afghanistan and Iraq wars has been held accountable, let alone prosecuted, and yet a publisher who exposed such crimes is potentially facing a lifetime in jail," she added.

aw, jcg/rt (dpa, AFP, AP)