Mauritius Prime Minister Navin Ramgoolam has said his government is considering legal action against the United Kingdom over delays in ratifying the agreement on the Chagos Islands.

Speaking to local newspaper Defi Media, Ramgoolam said Mauritius was "exploring legal avenues" in the dispute and had begun consulting international law firms while awaiting the formal transfer of the territory.

Under the proposed deal, the United Kingdom would hand sovereignty of the archipelago to Mauritius while leasing back the Diego Garcia base for military use.

Mauritian officials have expressed growing frustration over the stalled ratification process. 

Ministerial discussions earlier this week highlighted concerns that there was "no visibility" on when the treaty would be approved.

The uncertainty has caused alarm in Port Louis, where the agreement has been central to diplomatic planning and economic projections.

The ratification process was further complicated last month when Hamish Falconer said the UK was "pausing" the process while holding discussions with the United States.