The U.K. has agreed to hand sovereignty of the long-contested Chagos Islands, an archipelago of more than 60 islands in the Indian Ocean, to Mauritius, in a deal to secure the future of a strategically important U.

Activists have decried a deal that the UK will cede sovereignty of the Chagos Archipelago to Mauritius with the exception of Diego Garcia.

Mauritius has long argued it was forced to give up the islands in 1965 in return for independence from Britain