Julian Assange walks away a free man after he admits to one count of espionage during his US plea deal.

The WikiLeaks founder is on his way home to Australia after appearing in a court on the US Pacific Island territory of Saipan.

After pleading guilty to one count of conspiracy to obtain and disclose national defence information during the three-hour hearing, the Wikileaks founder was sentenced to time served, 62 months - all of which he has already spent in a British prison.

For many years, the US tried to prosecute Assange for the publication of thousands of classified and diplomatic documents on the Afghanistan and Iraq wars - which they said endangered lives.

Julian Assange walks away a free man after he admits to one count of espionage during his US plea dealReuters

For many years, the US tried to prosecute Assange for the publication of thousands of classified and diplomatic documents on the Afghanistan and Iraq wars - which they said endangered lives.

Assange and his lawyers have been fighting the extradition for over a decade. He had long claimed that the case against him was politically motivated.

Speaking to the court in Saipan, he said: “Working as a journalist I encouraged my source to provide information that was said to be classified in order to publish that information," he told the court.

“I believed the First Amendment protected that activity but I accept that it was ... a violation of the espionage statute.”

Assange and his lawyers have been fighting the extradition for over a decade

Judge Ramona V. Manglona accepted his guilty plea, noting that the US government indicated there was no personal victim from Assange's actions.

She wished an “early happy birthday” to Assange, who turns 53 next week.

“I hope you will start your new life in a positive manner,” she said.