Assange has spent the past five years in London's high-security Belmarsh prison and nearly seven years before that holed up at the Ecuadorian embassy in the English capital trying to avoid arrest. He maintains his extradition is politically motivated.

Assange is wanted for 17 counts of violating the U.S. Espionage Act, obtaining secret military documents and conspiring to hack into a Pentagon computer network. If convicted, he could face a sentence of up to 175 years in prison.

Mr Assange founded the Wikileaks website in 2006. It claims to have published more than 100 million documents, including many confidential or restricted official reports related to war, spying and corruption.