WASHINGTON – WikiLeaks founder Julian Assange was arrested Thursday to face a U.S. charge that he conspired to hack military computers after Ecuador's government ended his seven years of self-imposed exile and expelled him from its London embassy.

Police in the United Kingdom dragged Assange from the front door of the embassy Thursday morning. He now faces extradition to the United States.

In an indictment revealed Thursday morning, U.S. authorities say Assange conspired with former Army intelligence analyst Chelsea Manning to steal and publish huge troves of classified documents. Prosecutors said Assange at one point tried to help Manning crack a password to access military computers where the information was stored.

Over four months in 2010, Manning downloaded hundreds of thousands of secret reports on the wars in Iraq and Afghanistan, as well as State Department cables and information about detainees in Guantanamo Bay, Cuba. Manning turned the records over to WikiLeaks, which passed them to journalists and published them on the internet.

Prosecutors said it was one of the most extensive leaks of classified secrets in U.S. history.

Assange is charged with conspiracy to commit computer intrusion. The charge, delivered by a federal grand jury in March 2018 but kept secret until Thursday, carries a maximum sentence of five years in prison.

Barry Pollack, a U.S. lawyer for Assange, criticized the arrest and said Assange would need medical treatment that had been denied for seven years.

"It is bitterly disappointing that a country would allow someone to whom it has extended citizenship and asylum to be arrested in its embassy," Pollack said." Once his health care needs have been addressed, the UK courts will need to resolve what appears to be an unprecedented effort by the United States seeking to extradite a foreign journalist to face criminal charges for publishing truthful information."

Indictment:Julian Assange indictment: Read the grand jury indictment against the WikiLeaks founder

Assange had sheltered in Ecuador's embassy since seeking asylum there in 2012. London's Metropolitan Police moved in after Ecuador formally withdrew its asylum for Assange, an Australian native, and revoked his Ecuadorian citizenship. Plainclothes officers escorted him from the embassy Thursday.

In a British court Thursday, Judge Michael Snow issued a guilty verdict against Assange for breaching his bail conditions. Assange, who appeared in the Westminster Magistrates' Court where his supporters packed the public gallery, faces a sentence of up to 12 months in prison for the conviction.

British Prime Minister Theresa May said Assange’s arrest shows "no one is above the law."

The arrest followed months of carefully orchestrated diplomatic maneuvering by the Ecuadorian government that had long soured on its relationship with Assange. In a videotaped statement, Ecuadorian president Lenin Moreno said his country's patience "has reached its limit," citing bizarre behavior inside the embassy and violations of the country's demand that he stop interfering in the affairs of other governments.

Moreno described it as a “sovereign decision” as a result of “repeated violations to international conventions and daily life.”

Assange was taken into custody on a 2012 warrant for jumping bail while facing extradition to Sweden on sexual assault allegations. The Swedish accusations have since been dropped, but he was still wanted for the bail violation. The Justice Department said it was seeking his extradition to the United States.

That process can be a lengthy one. He will be entitled to a hearing in London where he can dispute the U.S. request. "What he’s going to do is to say that the extradition request is entirely political and its intention is to punish him for Wikileaks," said John Hardy, a London-based lawyer who specializes in extradition.

That could take as long as two years if Assange appeals to the United Kingdom's highest court, Hardy said.

The U.S. charges center on his interactions with Manning. Prosecutors said Assange encouraged her to leak classified secrets to the anti-secrecy group and tried to help her crack a password to Defense Department computers that stored classified secrets. That would have allowed Manning to log on to the computer network with someone else's username.

The indictment said investigators obtained messages between the two in which Manning provided Assange "part of a password" on March 8, 2010. Two days later, Assange asked for more information about the password and indicated that he had been trying to crack the password but so far had not succeeded.

Prosecutors said Assange also encouraged Manning to look for more classified information to disclose. On March 7, 2010, Manning and Assange discussed the Guantanamo records, according to the indictment. Manning told Assange the next day that “after this upload, that’s all I really have got left,” the indictment said. Assange replied that “curious eyes never run dry in my experience," the indictment said.

Separately, Assange has been under scrutiny for years for WikiLeaks’ role in publishing government secrets.

WikiLeaks, the transparency group that he founded, was also front and center of the 2016 presidential election for leaking emails hacked from the Democratic National Committee. During the presidential campaign, then-candidate Donald Trump repeatedly praised the organization, saying numerous times at rallies, "I love WikiLeaks."

Federal prosecutors have said the emails were stolen by hackers working for Russia's military intelligence service, which gave them to WikiLeaks as part of an effort to sway the presidential election in Trump's favor. The charges revealed Thursday are unrelated to that effort.

Moreno, the Ecuadorian president, said Assange "will not be extradited to a country where he could suffer torture or the death penalty. " He said the British government confirmed that in writing.

In a list of grievances, Moreno said Assange had installed prohibited electronic equipment in the embassy, blocked security cameras and even "accessed the security files of our embassy without permission." He said Assange also had "confronted and mistreated the diplomatic guards."

British Foreign Secretary Jeremy Hunt told reporters Thursday that the arrest shows that "no one is above the law."

"Julian Assange is no hero," he said. Hunt said the operation came after "years of careful diplomacy" and praised Moreno for his "very courageous decision."

"It's not so much Julian Assange being held hostage in the Ecuadorian Embassy," Hunt said. "It’s actually Julian Assange holding the Ecuadorian Embassy hostage in a situation that was absolutely intolerable for them."

Assange-Ecuador:Ecuador accuses Julian Assange of violating asylum deal in London embassy

Ecuador president Enough guarantees for WikiLeaks founder Julian Assange to leave embassy, return to UK

Assange took refuge in the embassy to avoid extradition to Sweden for questioning over rape allegations. Assange, an Australian national, chose to remain in the embassy out of fear that the United States would immediately seek his arrest and extradition over the leaking of classified documents to WikiLeaks by Manning.

Wikileaks said in a Thursday tweet that "Powerful actors, including CIA, are engaged in a sophisticated effort to dehumanize, delegitimize and imprison him."

Assange, who was granted Ecuadorian citizenship last year in an apparent effort to designate him a diplomat and allow him to go to Russia, sued Ecuador for violating his rights as an Ecuadorian.

He pressed his case in local and international tribunals on human rights grounds, but both ruled against him.

In 2011, the leftist Ecuadorian government that initially offered asylum to Assange had been embroiled in a diplomatic row with the United States involving a leaked U.S. diplomatic cable. U.S. ambassador to Ecuador Heather Hodges was expelled after WikiLeaks leaked the document that alleged widespread corruption within the Ecuadorian police force, the BBC reported.

Assange first got a taste of tapping into unauthorized material when he became a hacker in 1987. Four years later he was convicted of hacking into the master terminal of Nortel, a Canadian multinational telecommunications corporation, The New Yorker reported.

Opinion:Julian Assange deserves a Medal of Freedom, not a secret indictment

Report:Paul Manafort met secretly with WikiLeaks founder Julian Assange

In 2006, Assange established WikiLeaks as a site for publishing classified information and within a decade had posted more than 10 million documents often embarrassing to governments.

While gaining the backing of some world figures, including leaders of Brazil and Ecuador, he gained international notoriety after publishing information in 2010, which was leaked by a self-described whistleblower inside the U.S. Army, Bradley Manning, a transgender woman who later became known as Chelsea Manning. Manning spent nearly seven years in prison for leaking classified and sensitive military and diplomatic documents.

Contributing: William Cummings and Deirdre Shesgreen of USA TODAY; The Associated Press