The president of the Maldives has formally told the UK that it does not recognise the deal to hand over the Chagos Islands to Mauritius.

President Mohamed Muizzu's office told the BBC the Maldives had expressed its opposition to the "deeply concerning" deal in two written objections and a phone call with Deputy Prime Minister David Lammy.

The nation of tropical islands in the Indian Ocean is asserting sovereignty over the Chagos Islands and is threatening international legal action to press its claim.

UK Foreign Office minister Stephen Doughty has said the sovereignty of the Chagos Islands is a matter for Britain and Mauritius, not the Maldives.

A government source said international courts had already considered the question of sovereignty over the Chagos Islands and found in favour of Mauritius.