Wikileaks founder Julian Assange has pleaded guilty in a US court under a deal allowing him to walk free following a 14-year legal battle.

He entered the formal plea to a single charge in the Northern Mariana Islands, an American territory in the Pacific, two days after leaving a British prison.

In return, he was sentenced to time already served and released to fly to his native Australia and be reunited with his family.

US officials were pursuing the 52-year-old over a huge disclosure of secret files in 2010, which they said put lives in danger.

Assange arrived at court on Wednesday morning local time in Saipan, the capital of the Northern Mariana Islands, alongside a team that included Australia’s ambassador to the US Kevin Rudd.

At the hearing, Assange admitted a felony charge of conspiracy to obtain and disclose national defence information.

“Working as a journalist I encouraged my source to provide information that was said to be classified in order to publish that information,” Assange told the court.

But he emphasised that he believed he would be protected by the First Amendment of the US Constitution, which covers freedom of the press.

During the hearing, prosecutors said the WikiLeaks founder actively encouraged leaks of classified information. They said Assange told leakers that “top secret means nothing”.

After the sentencing, Assange’s lawyer, Barry Pollack, said: “Wikileaks’s work will continue and Mr Assange, I have no doubt, will be 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.”

Assange did not make any comments.

The US Department of Justice said in a statement following his sentencing that, due to his conviction, he was “prohibited from returning to the United States without permission”.

However, his wife Stella told the Reuters news agency that they would seek a pardon for Assange.

Mrs Assange took to X, formerly Twitter, after he walked free to express her emotion.

“I can’t stop crying,” she wrote.