LONDON – WikiLeaks founder Julian Assange, appearing before a British court Thursday, said he would not surrender to a U.S. extradition request as he defended his efforts to steal classified American government records as journalism.

"Not for doing journalism that's won many, many awards and affected many people," the Australian, 47, said by video link from Belmarsh Prison, a high-security jail in south-east London. Assange looked relaxed, dressed in jeans, a white T-shirt and a dark blazer as he addressed Judge Michael Snow at Westminster Magistrates court.

Assange was not handcuffed during his brief appearance.

Thursday's hearing was the first in a case likely to drag on for months, if not years. U.S. authorities are seeking Assange's extradition because the Department of Justice has charged him with conspiring to break into a Pentagon computer system to reveal a large cache of top-secret files on everything from the war in Afghanistan to diplomatic letters between State Department officials and U.S. ambassadors.

The court on Thursday scheduled a further procedural hearing date for May 30. Snow said the first substantive action related to the case would likely commence June 12.

"The charges relate to one of the largest compromises of classified information in the history of the U.S.," said Ben Brandon, a lawyer representing the U.S. government.

Brandon said that the documents Assange downloaded from the Pentagon computer included 90,000 war reports related to Afghanistan, 400,000 from the Iraq War, 800 Guantanamo Bay detainee assessments and 250,000 State Department cables.

About three dozen activists gathered outside the court to protest Assange's potential extradition. They waved banners and held up photos of Assange with his mouth covered with the American flag. "Civilized people do not extradite publishers of war crimes to war criminal regimes, do they?" one such sign read.

"Free Assange" and "No extradition" read others.

"It's about journalistic freedom," Icelandic investigative reporter and WikiLeaks' editor-in-chief Kristinn Hrafnsson said speaking to reporters outside the court.

Some protesters later temporarily blocked a road outside the court.

The hearing comes one day after a separate British court sentenced Assange to 50 weeks in a British prison for skipping bail seven years ago and seeking refuge in Ecuador's Embassy in London. Assange apologized to the court and said he was "struggling with terrifying circumstances" when he decided to hole up in the embassy.

When he arrived at Southwark Crown Court in a prison van on Wednesday, Assange raised a clenched fist, a gesture he repeated as he left the court to be returned to prison. He white hair and long beard were trimmed, a marked contrast to Assange's disheveled appearance when he was carried out head-first of Ecuador's embassy on April 11, looking frail and disoriented, by British police.

The U.S. alleges that Assange, who is known for his exceptional computer hacking skills, assisted Chelsea Manning, then a soldier in the U.S. Army, in cracking a password stored on U.S. Department of Defense computers. WikiLeaks subsequently published thousands of classified U.S. military and diplomatic cables and images, including video footage allegedly showing U.S. soldiers killing civilians in Iraq.

Manning served nearly seven years of a 35-year sentence for theft and espionage for helping to deliver classified documents to WikiLeaks. Manning's sentence was later commuted by former President Barack Obama and she was released in 2017.

Assange faces up to five years in a U.S. prison if convicted of conspiracy charges.

Journalist or criminal?Julian Assange notorious for leaks of US secrets

Assange was arrested last month inside the Ecuadorian embassy after the South American country revoked his political asylum. He sought asylum in the embassy in June 2012 to avoid extradition to Sweden, where he was wanted for questioning over rape and sexual assault allegations. At the time, Assange's legal team believed that if he were extradited to Sweden he would subsequently be extradited to the U.S.

Assange denies the rape and sexual assault allegations, which were dropped because his residence in Ecuador's embassy stymied the investigation, and because the statute of limitations expired. Swedish prosecutors have indicated that they are considering a request from one of Assange's alleged victims to re-open the rape probe.

If that happens, Assange could face a competing new claim for extradition to Sweden.

Anand Doobay, a London-based lawyer who specializes in extradition law, said that Assange's case is now further complicated by his 50-week sentence. He said that extradition cases can take "a very long time" and that the decision may ultimately reside with Britain's secretary of state, who will need to be satisfied that Assange would not face the death penalty in the U.S. or be charged with additional crimes.

He said that if Sweden decided to renew its request for extradition based on the rape probe, the secretary of state would also need to decide which request to favor.

"There are significant legal obstacles for the U.S. case," said Daniela Nadj, a professor of law at Queen Mary, University of London, adding that "many questions need to be answered." Among them: If Sweden decides to renew its extradition claim whether a rape allegation should take precedence over a hacking one.

"Right now Julian will be fighting a battle against despair and despondency," Lauri Love, a British activist who won a U.S. extradition appeal in 2018 for allegedly hacking into the computer systems of the FBI, U.S. Federal Reserve and NASA, told USA TODAY outside the court in London where he showed up to support Assange.

"He'll be facing the same worries I had," Love, 34, who said he is a friend of Assange's, noted. "Being sent to a place where you have no friends, no family and where you are facing the prospect of facing many people who consider you to be the enemy."

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