The United States on Wednesday urged a judge in London not to release WikiLeaks founder Julian Assange on bail, as it seeks to appeal a decision to block his extradition to face charges for publishing secret documents.

Lawyer Clair Dobbin, representing the government in Washington, told Westminster Magistrates Court there were "no conditions that could guarantee his surrender" if he were freed from custody.

Assange spent years in the Ecuadorean embassy to avoid extradition from the UK
Assange spent years in the Ecuadorean embassy to avoid extradition from the UK AFP / Justin TALLIS

Assange, 49, who was in court to hear the application, is seeking to be released on bail, after an unexpected decision on Monday to block his removal to the United States on the grounds he was a suicide risk.

Crowds of his supporters gathered outside the court in anticipation of the decision, which is expected later on Wednesday.

IMAGESJulian Assange's fiancee Stella Moris and WikiLeaks editor-in-chief Kristinn Hrafnsson arrive at Westminster Magistrates' Court, in central London, ahead of the bail hearing in Assange's extradition case. Lawyers for the WikiLeaks founder will argue
IMAGESJulian Assange's fiancee Stella Moris and WikiLeaks editor-in-chief Kristinn Hrafnsson arrive at Westminster Magistrates' Court, in central London, ahead of the bail hearing in Assange's extradition case. Lawyers for the WikiLeaks founder will argue he should be released from a British prison on bail, pending Washington's appeal against a decision not to extradite him to the United States. AFPTV / Mathilde BELLENGER

Dobbin said the court "should be under no doubt about his resources to abscond", pointing to his previous flouting of bail conditions, and an offer of political asylum, notably from Mexico.

But Assange's lawyer, Edward Fitzgerald, said he should be freed.

Mexico said it was ready to offer political asylum to  Assange
Mexico said it was ready to offer political asylum to Assange AFP / Pedro PARDO

"We say after all this time, after the long proceedings over a year... the court has given a decision and the decision has been that he should be discharged," he added.

Assange is wanted to face 18 charges relating to the 2010 release by WikiLeaks of 500,000 secret files detailing aspects of military campaigns in Afghanistan and Iraq.

Supporters of Assange celebrated outside the court in London after a judge ruled that he should not be extradited to the United States
Supporters of Assange celebrated outside the court in London after a judge ruled that he should not be extradited to the United States AFP / DANIEL LEAL-OLIVAS

Washington claims he helped intelligence analyst Chelsea Manning steal the 2010 documents before exposing confidential sources around the world.

He faces a possible 175-year sentence if convicted but Assange and his lawyers have long argued the case against him is politically motivated.

Members of the media and crowds of his supporters gathered outside the court in anticipation of the decision
Members of the media and crowds of his supporters gathered outside the court in anticipation of the decision AFP / JUSTIN TALLIS

He was not released immediately after Monday's ruling and remained at the high-security Belmarsh prison in southeast London until the bail application.

A previous request for bail in March on the grounds he was vulnerable to Covid-19 while behind bars was rejected because the judge assessed he was likely to abscond.

Timeline on Julian Assange, the Australian founder of WikiLeaks.
Timeline on Julian Assange, the Australian founder of WikiLeaks. AFP / Sophie RAMIS

Assange sought sanctuary in Ecuador's embassy in 2012, after Sweden issued an arrest warrant in connection with sexual assault allegations.

He spent seven years at the South American country's London mission until the government in Quito revoked his citizenship.

British police dragged him out and arrested him in 2019.

He was then sentenced to 50 weeks in jail for breaching his bail terms in connection with the Swedish case, which was later dropped due to lack of evidence.

The UN called the sentence "disproportionate".

Assange's long-running legal woes have become a cause celebre for media freedom, even though the judge hearing the case said he did have a case to answer.

Judge Vanessa Baraitser on Monday said he would have been "well aware" of the effects of his leaking of secret documents, and his actions went "well beyond" the role of a journalist.

But she said extradition would be "oppressive" as his mental health would probably deteriorate in the US penal system, "causing him to commit suicide".

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 in custody despite supervision.

UN rapporteur on torture Nils Melzer applauded the decision to block his extradition, and said he should be freed and compensated for his ordeal, which amounted to arbitrary detention.

The United States has called the ruling "extremely disappointing" and has faced calls from WikiLeaks, as well as rights and media freedom groups to drop the appeal.