WikiLeaks founder Julian Assange told a London court on Thursday his work had protected "many people" and refused to agree to be extradited to the United States to face trial for one of the largest compromises of classified information in history.

The United States has requested the extradition of Assange, who was dragged from the Ecuadorean Embassy in London on April 11, and has charged him with conspiracy to commit computer intrusion, which carries a maximum penalty of five years.

Asked at a preliminary hearing at Westminster Magistrates' Court whether he agreed to be extradited to the United States, Assange, appearing via a video link from a British prison, said: "I do not wish to surrender for extradition. I'm a journalist winning many, many awards and protecting many people."