Mauritius called the  an "illegal colonial occupier", after it ignored a UN mandated deadline to return the  Islands, a small archipelago in the Indian Ocean, to Mauritius. The United Nations had given  six months to process the transfer. Mauritius has argued that the  Islands has been a part of its territory since at least the 18th century, till the  broke the archipelago away from Mauritius in 1965 and the islands of Aldabra, Farquhar, and Desroches from Seychelles in the region to form British Indian Ocean Territory. In June 1976, after Seychelles gained independence from the , the islands of Aldabra, Farquhar, and Desroches were returned by the . After independence, Mauritius had proposed an exchange allowing the  to let the  use the  Islands for defence purposes till those needs ceased, in exchange for increasing the quota of sugar imports into the , a move that would contribute to Mauritius' economy. The  rejected the proposal stating that the  could not be involved in any treaty despite using the islands themselves.
Which of the following countries has been replaced with '' in the passage above?
Mauritius called the UK an "illegal colonial occupier" after it ignored a UN mandated deadline to return the Chagos Islands, a small archipelago in the Indian Ocean, to Mauritius. The United Nations had given UK six months to process the transfer, a move the UK and the US have bitterly resisted.