The United States on Thursday announced charges against Wikileaks co-founder Julian Assange, who was arrested at the Ecuadorian embassy in London earlier, accusing him of helping Chelsea Manning break into classified computers at the Pentagon.

According to the Metropolitan Police Service (MPS), Assange was taken into custody at a central London police station "where he will remain, before being presented before Westminster Magistrates' Court as soon as possible."

The MPS said that the force was invited into the embassy by the ambassador, following the Ecuadorian government's withdrawal of asylum.

Footage shot by Ruptly, a video news agency, showed a frantic-looking Assange, with a large white beard, being carried down the embassy steps by several men into a police van.

Britain has guaranteed to Ecuador that Assange will not be extradited to a country that has the death penalty, Ecuadorean President Lenin Moreno said on Thursday after Assange was arrested in London.

“In line with our strong commitment to human rights and international law, I requested Great Britain to guarantee that Assange would not be extradited to a country where he could face torture or the death penalty,” Moreno said in a video posted on Twitter.

“The British government has confirmed it in writing, in accordance with its own rules.”

Kremlin spokesman Dmitry Peskov said Moscow hopes that Assange's rights will not be violated.

Assange has been living at the embassy in London's plush Knightsbridge district since 2012 when he sought refuge there after being accused of sexual assault in Sweden — allegations that have since been dropped.

The 47-year-old Australian was due to appear in court later on Thursday. He faces prosecution for breaching the conditions of his bail in Britain in 2012.

He had refused to leave the embassy, fearing ultimate extradition to the United States where WikiLeaks said he faces charges over his website publishing huge caches of hacked State Department and Pentagon files.

WikiLeaks had warned last week that a revocation of Assange's asylum could happen within "hours to days", citing sources in Ecuador.

'Truman Show' in embassy

WikiLeaks on Wednesday had claimed that it was being blackmailed by "dubious characters" who had obtained security camera footage of Assange inside the embassy.

Kristinn Hrafnsson, editor-in-chief of WikiLeaks, accused Ecuador authorities of gathering the images, which he said then found their way into the hands of a group in Spain, who were demanding $3 million (2.7 million euros) not to publish them.

The documents include thousands of photographs and gigabytes of video footage showing Assange meeting with lawyers and visitors and of him receiving a medical check-up.

"Since (President Lenin) Moreno took power in Ecuador (in 2017), Julian Assange has been living in a Truman Show type situation" with constant surveillance, Hrafnsson claimed.

The editor also accused embassy staff of photocopying a legal document belonging to Assange's lawyer Aitor Martinez.

WikiLeaks believes that the United States is working with Ecuador to extradite Assange to face charges, and that the embassy documents were "quite likely shared with the Trump administration", although it offered no proof of this.

Ecuador had said on Tuesday it was reassessing Assange's asylum claim.