Assange walked out of the courtroom as a free man into the bright Saipan sunshine, raising one hand to a gaggle of the world’s press before departing by car for the airport where he caught a flight to the Australian capital Canberra, reported CNN.

Assange’s US lawyer Barry Pollack was quoted as saying by the American news channel that he had “suffered tremendously in his fight for free speech and freedom of the press”.

“The prosecution of Julian Assange is unprecedented in the 100 years of the Espionage Act,” Pollack told reporters. “Mr. Assange revealed truthful, newsworthy information … We firmly believe that Mr. Assange never should have been charged under the Espionage Act and engaged in (an) exercise that journalists engage in every day.”

Earlier on Tuesday, he left a prison in the UK and headed to a US courtroom on the Northern Mariana Islands to formalize the agreement.

“I am, in fact, guilty of the charge,” Assange told the court in Saipan as quoted by CNN.

Assange's wife Stella wrote on X: "Julian Assange Free At Last!!!."

Assange, detained first in prison then under house arrest, took refuge in Ecuador's embassy in London in 2012 after losing his appeal to the UK Supreme Court against extradition to Sweden, where a judicial investigation was initiated against him in connection with allegations of sexual misconduct. However, he was not formally charged.

Assange's WikiLeaks site published confidential diplomatic information, and he has been detained since 2010.