Washington said the deal protected the long-term, secure and effective operation of the strategic military base.

Britain on Thursday said it would give up sovereignty of a remote Indian Ocean archipelago to Mauritius but will maintain there a strategic military base that it shares with the United States, in what US President Joe Biden described as a "historic agreement".

While the UK and US retain a key strategic military base in the Indian Ocean, the two governments remain apprehensive over the security of the island.