WikiLeaks founder Julian Assange on Tuesday was granted permission by a U.K. court to appeal his extradition to the U.S., where he is wanted on spying charges.

Assange will therefore not be extradited immediately, the court said.

The ruling from the Royal Courts of Justice in London means Assange will have the opportunity to pursue a new hearing, unless the U.S. provides “satisfactory assurances” on certain aspects that would address his grounds of appeal.

The court said it would give the U.S. three weeks to give assurances that Assange is permitted to rely on the First Amendment of the U.S. Constitution, that he is not prejudiced at trial by reason of his nationality, that he is afforded the same First Amendment protections as a U.S. citizen and that he would not be subject to the death penalty.

An appeal hearing will be granted if those assurances are not given. A further hearing on May 20 will determine whether the assurances provided are satisfactory, the court said.

The 52-year-old has been battling extradition for more than a decade. In that time, Assange has spent seven years in self-exile in the Ecuadorian embassy in London and the last nearly five years at Belmarsh, a high-security prison on the outskirts of the U.K. capital.

Assange is wanted in the U.S. on 18 charges, including 17 under the Espionage Act and one under the Computer Fraud and Abuse Act.

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