Britain on Thursday said it would give up sovereignty of the Chagos Islands to Mauritius, but under what President Joe Biden called a "historic agreement" will keep a strategic Indian Ocean military base with the United States.

The U.K. says it has reached a "historic" deal to cede the Chagos Archipelago in the Indian Ocean to the Republic of Mauritius, thus surrendering the final colony of Britain's once-sprawling African empire.

The UK has given up a top secret island to Mauritius after years of arguments and negotiations. The Chagos Islands in the Indian Ocean has been strictly out of bounds since 1973 ever since the UK and US used the island as a military base. It is has been at the centre of a long-running dispute between the UK and Mauritius.

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.

Sir Keir Starmer has given up the Chagos Islands, handing the Indian Ocean territory to Mauritius. The islands were British-owned from 1814 but have now been signed away by the Government in a deal that it claimed would safeguard global security by ending a long-running dispute.

The UK will cede sovereignty of the Chagos Islands to Mauritius, but indigenous people from a tiny island that houses a US military base shrouded in secrecy will not be allowed to return

Operation of Diego Garcia, a strategic military base jointly operated by the UK and US, is protected by the agreement.

Under the deal reached by Sir Keir Starmer with Mauritius Prime Minister Pravind Jugnauth, the British Indian Ocean Territory (BIOT) or Chagos Islands is to be handed back more than five decades after the rest of Mauritius won independence from the UK.