Julian Assange's lawyer says WikiLeaks founder 'cannot, and should not, be silenced'

WikiLeaks founder Julian Assange is on a flight home to Australia after pleading guilty to a felony espionage charge in a US court, under a deal negotiated with the Department of Justice.

The resolution, which played out in the US District Court on the island of Saipan, brings to a close more than a decade of legal fighting sparked by WikiLeaks' release in 2010 of a cache of classified US defence documents alleging US war crimes in Afghanistan and Syria.

Speaking outside court, Assange's US lawyer Barry J Pollack called the prosecution of his client "unprecedented" and said Assange should never have been charged with an espionage offence for publishing the documents.

"He has suffered tremendously in his fight for free speech, for freedom of the press, and to ensure that the American public and the world community gets truthful and important newsworthy information," Mr Pollack said.

"It is appropriate, though … for the judge, as she did today, to determine that no additional incarceration of Mr Assange would be fair."

Mr Pollack said WikiLeaks would continue its work, which often involves publishing leaked government documents, and Assange himself would remain "a continuing force for freedom of speech and transparency in government".

"He is a powerful voice and a voice that cannot, and should not, be silenced," he said.

Mr Pollack added that Assange had refused to plead guilty to any charges that would have "required him to accept allegations that are simply not true" — but the charge of accepting and publishing national security documents was acceptable as he had done just that "in the world's interest".

Assange's Australian lawyer, Jennifer Robinson, said it was a "historic day" and the deal had come as a "huge relief to Julian Assange, to his friends, family, supporters, to us, and to everyone who believes in free speech around the world".

"There has been a global movement behind Julian to protect free speech and it is because of that global movement of support that today's outcome is possible," she said.

"In particular, I want to thank our prime minister, Anthony Albanese, for his statesmanship, his principled leadership, and his diplomacy, which made this outcome possible."

Assange flew into Saipan, in the Northern Mariana Islands, on Wednesday morning as part of a plea deal that saw him sentenced to time served in exchange for a guilty plea to the espionage charge, which carried a maximum penalty of up to 10 years in prison.

Chief Judge Ramona Manglona, an Obama appointee, approved the plea deal though she said if Assange had faced court in 2012 she would have been less inclined to accept it, as it was only the passage of time that showed no one had been physically harmed due to the leak.

She sentenced Assange to time served, given the five years he had spent in the UK's Belmarsh Prison while he fought extradition to the United States.

The plea deal resolves a 14-year battle over Assange's future, however, it has sparked renewed concerns about the case's potential chilling effect on press freedom, with free speech advocates highlighting the need for Assange's style of activist journalism to keep governments honest.

The resolution to Assange's case also follows years of diplomacy from the Australian government, with the case becoming a thorny issue in the US-Australia relationship.

Speaking after the court accepted the plea deal, Australian Prime Minister Anthony Albanese said the resolution was "a welcome development" but it should be recognised that the US court proceedings were "sensitive and should be respected".

"This isn't something that has happened in the last 24 hours," Mr Albanese said.

"This is something that has been considered, patient, worked through in a calibrated way, which is how Australia conducts ourselves internationally."

He added that Assange had been provided with consular assistance throughout the plea deal process, including the presence of its ambassador to the United States, Kevin Rudd, and ambassador to the United Kingdom, Stephen Smith, at the hearing.

Assange spent five years in the UK's Belmarsh Prison fighting moves to extradite him to the United States in relation to the WikiLeaks publications.

He had previously spent seven years in the Ecuadorian embassy in London fighting moves to extradite him to Sweden on a charge of rape, saying he was concerned he would be extradited to the United States if he went to Sweden in person to fight the charge.

The UK government maintained a 24-hour guard outside the embassy for the majority of his stay there, preventing his escape to Ecuador, where he had been granted asylum.

The charge in question was eventually dropped in 2019, with prosecutors citing insufficient evidence to proceed.

Assange is due to arrive in Australia on a flight to Canberra later on Wednesday.