WASHINGTON — WikiLeaks founder Julian Assange will plead guilty to a felony charge in a deal with the U.S. Justice Department that will allow him to walk free and resolve a long-running legal saga that spanned multiple continents and centered on the publication of a trove of classified documents.

Assange left a British prison on Monday and will appear later this week in the U.S. federal court in the Northern Mariana Islands, a U.S. commonwealth in the Western Pacific. He’s expected to plead guilty to an Espionage Act charge of conspiring to unlawfully obtain and disseminate classified national defense information, the Justice Department said in a letter filed in court.

The guilty plea, which must be approved by a judge, brings an abrupt conclusion to a criminal case of international intrigue and to the U.S. government’s years-long pursuit of a publisher whose hugely popular secret-sharing website made him a cause celebre among many press freedom advocates who said he acted as a journalist to expose U.S. military wrongdoing. Investigators, by contrast, have repeatedly asserted that his actions broke laws meant to protect sensitive information and put the country’s national security at risk.

He is expected to return to Australia after his plea and sentencing, which is scheduled for Wednesday morning, local time in Saipan, the largest island in the Mariana Islands. The hearing is taking place there because of Assange’s opposition to traveling to the continental U.S. and the court’s proximity to Australia.

Attorneys for Assange didn’t immediately respond to a request for comment on Monday.