LONDON (DPA) - Britain rejected a claim by Mauritius over the Chagos Islands on Friday (Nov 22), six months after the United Nations said London should end its "colonial administration" of the Indian Ocean territory.

The UN General Assembly voted in May to ask Britain to hand over the islands within six months to allow Mauritius to complete "decolonisation" of its territory.

Mauritian Prime Minister Pravind Jugnauth said the passing of the six-month deadline makes Britain an illegal colonial occupier of the islands, the BBC and other media reported.

"The UK has no doubt as to our sovereignty over the British Indian Ocean Territory, which has been under continuous British sovereignty since 1814," the British foreign office said in a statement.

"Mauritius has never held sovereignty over the (territory) and the UK does not recognise its claim," it said.

Britain separated the Chagos Archipelago from Mauritius in 1965. It leased the main island, Diego Garcia, to the United States as a military air base. The lease was extended for 20 years in 2016.

Speaking in a UN court last year, former Mauritian president Anerood Jugnauth said his country was coerced into a 1968 independence agreement with Britain that allowed hundreds of Chagos islanders to be relocated against their will.

The Chagos Islanders' Movement, which has campaigned on behalf of more than 1,500 people, claims the islanders were "forced out and dumped in the slums of Mauritius and the Seychelles".

London has suggested it would cede sovereignty of the islands if they were no longer needed for defence purposes.