Wikileaks founder Julian Assange has arrived at a United States Pacific territory court, 14 years after he leaked troves of secret state information and ended up in a British maximum security prison.

The saga that started with Assange holed up in Ecuador’s London embassy, before leading him into solitary confinement in Belmarsh prison in the United Kingdom, is rapidly coming to an end.

A private jet carrying Assange, his support team including Australia’s ambassador to the UK Stephen Smith landed in Saipan, the capital of the Northern Mariana Islands, about 6.15am on Wednesday.

Later, Assange was joined by Australia’s ambassador to the US Kevin Rudd who escorted the Australian, dressed in a suit, into the US District Court in the territory.

Assange, 52, agreed on Tuesday to plead guilty to a single criminal count of conspiring to obtain and disclose classified US national defence documents, according to court filings.

By the end of the day he was on a plane to the islands via Thailand.

He will be sentenced for time served at 9am on Wednesday at a hearing in a courtroom about 3500km from Darwin.

An updated court document states that Assange has been summoned to the third floor of the District Court.

There is one count listed: conspiring to unlawfully obtain and disseminate classified information relating to the national defence of the United States, in violation of 18 USC, section 793(g).

Another court document states that US Justice Department officials “anticipate that the defendant will plead guilty to the charge.”

Once the proceedings are over, Wikileaks and his family say Assange will be free to return to Australia, which could be as soon as Wednesday evening.

For his supporters, it is a moment of jubilation.

“It’s a great victory for freedom of expression and also justice,” Greg Barns, SC, legal advisor to the Australian Assange Campaign, told AAP.

“Julian faced the prospect of over 170 years in a US jail if he’d been convicted of the charges for which the Americans were seeking to extradite him.

But former Australian high commissioner to the UK Alexander Downer, who served while Assange was seeking asylum in the Ecuadorian embassy in London, said he doubted Australians would have sympathy for him.

“What he did was a criminal offence, and it was a terrible thing to do, morally as well, and endangering people’s lives in that way,” he told the BBC.

Australia had long called for the US to end its pursuit of Mr Assange, who faced spying charges.

Prime Minister Anthony Albanese had directly raised the issue with US President Joe Biden and a group of politicians from across Australia’s political spectrum converged on Washington in September to lobby US decision-makers.

“Regardless of the views that people have about Mr Assange’s activities, the case has dragged on for too long,” Mr Albanese said. 

Assange’s family are relieved at his release, with his father John Shipton praising the Australian government for its efforts to end the “persecution” of his son.

“I am absolutely elated – it is as though a huge burden has been lifted,” he said on Tuesday.

Assange’s mother, Christine Assange, said his release showed “the importance and power of quiet diplomacy”.

“Many have used my son’s situation to push their own agendas, so I am grateful to those unseen, hard-working people who put Julian’s welfare first,” she said. 

“The past 14 years has obviously taken a toll on me as a mother.”

Assange’s wife Stella said while there had been uncertainty about the situation leading up to her husband being released from prison, she was “elated” by the developments.

Assange’s brother Gabriel Shipton told Reuters that for “millions of people who have been advocating for Julian, it is almost time for them to have a drink and a celebration”.

Meanwhile, Mrs Assange late on Tuesday night made a public call for donations to pay the $US520,000 (about $A783,000) fee for the jet bringing her husband home.

Assange was “obligated” to pay the money to the Australian government, she said in a post on X, formerly known as Twitter.

This post was originally published on Michael West.