The UK is returning the Chagos Islands to Mauritius, but the important military base on Diego Garcia will remain under UK control.
The foreign secretary says this deal is important for national security because it ensures the base's long-term future.
The agreement will allow Chagossians, who were forced to leave the islands decades ago, to return.
However, some critics argue that the deal gives away a key military asset and that the Chagossians weren't properly consulted.
