WASHINGTON — WikiLeaks founder Julian Assange will plead guilty to a felony charge in a deal with the U.S. Justice Department that will free him from prison and resolve a long-running legal saga that spanned multiple continents and centered on the publication of a trove of classified documents, according to court papers filed late Monday.

Assange is scheduled to appear in the federal court in the Mariana Islands, a U.S. commonwealth in the Western Pacific, 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 célèbre 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.

Assange’s U.S. attorney, Barry Pollack, did not immediately return messages seeking comment Monday.