Assange 'will surrender' on Friday if UN rules against him

WikiLeaks Julian Assange says he will hand himself over to the authorities if the United Nations announces he has lost his case against arrest on Friday.

In a statement on the WikiLeaks Twitter feed, Assange said he would leave the Ecuadorian embassy in London at noon local time "to accept arrest by British police as there is no meaningful prospect of further appeal."

Assange has been holed up in the Ecuadorian embassy in west London for three and a half years in a bid to avoid extradition to Sweden over rape allegations, a charge he has denied.

The Australian fears he could eventually face extradition to the United States to be put on a trial over the leak of hundreds of thousands of classified military and diplomatic documents.

In September 2014, he filed a complaint against Sweden and Britain to the UN Working Group on Arbitrary Detention claiming his confinement in the embassy amounts to illegal detention.

Any decision by the group would not be legally binding, but other people have reportedly been released in the past on the basis of its rulings.