The governments of Britain and Mauritius have reached a final deal to settle the future of the Chagos Islands but have been barred from signing it by a British judge.

Britain signed a multi-billion dollar deal on the future of the Chagos Islands with Mauritius after a last-gasp injunction was overturned, securing itself a lease for the U.S.-UK Diego Garcia air base for the next century.

The Chagos Islands are in the middle of the Indian Ocean and home to a strategic military base on Diego Garcia.