Julian Assange pleads guilty at hearing in the Northern Mariana Islands

Julian Assange pleaded guilty to a felony at a United States federal courthouse in the Northern Mariana Islands on Wednesday and walked out of court a free man.

The Justice Department had reached an agreement for Assange to plead guilty to a single felony count of conspiring to unlawfully obtain and disseminate classified information. The judge in the case sentenced Assange to time served.

Speaking outside the court in Saipan following the hearing, Assange's chief U.S. lawyer, Barry J. Pollack, called the prosecution of Assange "unprecedented."

"[The Espionage Act] has never been used by the United States to pursue a publisher, a journalist," Pollack said.

"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 gets truthful and important newsworthy information," he continued. "We firmly believe that Mr. Assange never should have been charged under the Espionage Act and engaged in exercise that journalists engage in every day, and we are thankful that they do."

The WikiLeaks founder arrived at the U.S. territory, located in the western Pacific, to "formalize the plea deal," WikiLeaks said.

He was photographed arriving at the U.S. District Court in Saipan, the capital of the Northern Mariana Islands, Wednesday morning local time wearing a dark suit and brown tie. He did not take any questions from reporters, according to the AP.

Following the plea hearing, Assange is expected to travel to his native Australia.

Assange was photographed earlier Tuesday boarding a private plane in the United Kingdom after he reached a deal with prosecutors in the U.S. to plead guilty to a single felony count.

Assange had been accused by the United States of conspiring with Chelsea Manning, who, as an intelligence analyst in the U.S. Army, leaked to Assange hundreds of thousands of classified documents, including about 250,000 U.S. Department of State cables. WikiLeaks began publishing those documents in 2010.

"Julian Assange is free," WikiLeaks said in a statement posted to social media early on Tuesday.

Assange on Monday walked out of London's Belmarsh High Security Prison after more than five years at the facility, WikiLeaks said. He'd spent 1901 days there, the group said.

"He was granted bail by the High Court in London and was released at Stansted airport during the afternoon, where he boarded a plane and departed the UK," WikiLeaks said.

"After more than five years in a 2x3 metre cell, isolated 23 hours a day, he will soon reunite with his wife Stella Assange, and their children, who have only known their father from behind bars," WikiLeaks added.

Stella Assange, a longtime partner who married Assange in 2022, released a statement praising the "incredible movement" that had sprung up to protest Assange's detention and the U.S. charges against him.

"A movement of people from all walks of life, from around the world who support not just Julian, and not just us and our family, but what Julian stands for: Truth and justice," Stella Assange said. "We still need your help. What starts now with Julian's freedom is a new chapter."

ABC News' Alexander Mallin and Patrick Reevell contributed to this report.