The Chagos Islands have been a British territory since the 19th century and host an American and British military base.
British Prime Minister Keir Starmer has previously signed an agreement to return the archipelago to Mauritius. However, the Diego Garcia air base would be leased to the UK.
The process has been halted following criticism from US President Donald Trump, prompting a reaction from Mauritius.
We will do everything, diplomatically and legally, to complete decolonization, Foreign Minister Dhanajay Ramaful said.
