A British court ruled Tuesday that

Julian Assange

can't be extradited to the United States on espionage charges unless US authorities guarantee he won't get the death penalty, giving the WikiLeaks founder a partial victory in his long legal battle over the site's publication of classified American documents.

Two High Court judges said they would grant Assange a new appeal unless US authorities give further assurances within three weeks about what will happen to him. The ruling means the legal saga, which has dragged on for more than a decade, will continue — and Assange will remain inside London's high-security Belmarsh Prison, where

he has spent the last five years

.

Judges

Victoria Sharp and Jeremy Johnson

said the US must guarantee that Assange, who is Australian, "is afforded the same First Amendment protections as a United States citizen, and that the death is not imposed."

The judges said that if the US files new assurances, "we will give the parties an opportunity

to make further submissions

before we make a final decision on the application to leave to appeal." The judges said a hearing will be held May 20 if the US makes those submissions.

The US Justice Department

declined to comment

Tuesday.

Assange's supporters say he is a journalist

protected by the First Amendment

who exposed US military wrongdoing in Iraq and Afghanistan that was in the public interest.

Assange's wife

Stella Assange

told the WikiLeaks founder "is being persecuted because he has exposed the true cost of war in human lives."

"The Biden administration should not issue assurances.

They should drop this shameful case

, which should never have been brought," she said outside the High Court in London.

The ruling follows a two-day hearing in the High Court in February, where Assange's lawyer

Edward Fitzgerald

said American authorities were seeking to punish him for WikiLeaks' "exposure of criminality on the part of the US government on an unprecedented scale," including torture and killings.

The US government said Assange's actions

went beyond journalism

by soliciting, stealing and indiscriminately publishing classified government documents that endangered many people, including Iraqis and Afghans who had helped US forces.

The judges rejected six of Assange's nine grounds of appeal, including the allegation that

his prosecution is political.

They said that while Assange "acted out of political conviction... it does not follow however that the request for his extradition is made on account of his political views."

The judges also said Assange could not appeal based on allegations, made by his lawyers, that

the CIA developed plans to kidnap or kill Assange

during the years he spent holed up in the Ecuadorian Embassy in London, to prevent him from trying to flee.

The judges said "plainly, these are allegations of the utmost seriousness," but concluded

they had no bearing on the extradition request.

"Extradition would result in him being lawfully in the custody of the United States authorities, and the reasons (if they can be called that) for rendition or kidnap or

assassination

then fall away," the ruling said.

Freedom of speech

They accepted three grounds or appeal: the threat to Assange's freedom of speech, Assange's claim that he faces disadvantage because

he is not a US citizen

, and the risk he could receive the death penalty.

US authorities have promised Assange would not receive capital punishment, but the judges said that "

nothing in the existing assurance

explicitly prevents the imposition of the death penalty."

Jennifer Robinson

, one of Assange's lawyers, said that "even if we receive the assurances, we're not confident we can rely on them."

Assange, 52 years old, an Australian computer expert, has been indicted in the US on charges over Wikileaks' publication

in 2010

of hundreds of thousands of classified documents.

US prosecutors say he conspired with US army intelligence analyst

Chelsea Manning

to hack into a Pentagon computer and release secret diplomatic cables and military files on the wars in Iraq and Afghanistan.

Assange faces

17 counts undee the Espionage Act and one charge of computer misuse

. If convicted, his lawyers say he could receive a prison term of up to 175 years, although American authorities have said any sentence is likely to be much lower.

Assange's wife and supporters say his

physical and mental health have suffered

during more than a decade of legal battles and confinement.

Assange's legal troubles began in 2010, when he was arrested in London at the

request of Sweden

, which wanted to question him about allegations of rape and sexual assault made by two women. In 2012, Assange jumped bail and sought refuge inside the Ecuadorian Embassy.

The relationship between Assange and his hosts eventually subsided, and he was evicted from the embassy in April 2019. British police immediately arrested and imprisoned him

for breaching bail in 2012

. Sweden dropped the sex crimes investigations in November 2019 because so much time had elapsed.

A UK district court judge rejected the US extradition request in 2021 on the grounds that Assange was likely

to kill himself

if held under harsh US prison conditions. Higher courts overturned that decision after getting assurances from the US about his treatment. The British government signed an extradition order in June 2022.