The US government has given its official backing to the UK's plan to hand over the Chagos Islands to Mauritius and lease back an important military base.
In a statement, the US Department of State said it "supports the decision of the United Kingdom to proceed with its agreement with Mauritius concerning the Chagos archipelago".
It will come as a relief for the UK government after rapid changes in the position of US President Donald Trump on the deal, going from calling it an "act of great stupidity" to saying the deal was the "best" the prime minister could make.
The announcement comes ahead of talks between the US and Mauritius planned for next week.
In its statement, the US Department of State said that "the US reiterates its desire" for guaranteed "continued use" of the military base on Diego Garcia.
Diego Garcia is the largest island in the archipelago and is used by the UK and US armed forces. Under the new plan, the UK will lease back Diego Garcia for a period of 99 years.
Continuing on the military base would "advance US national security" and ensure the "security and stability across the Indian Ocean", the US Department of State added.
The US government had previously signalled it would back the deal worth £3.4bn ($4.6bn) that was signed by the UK in May.
At the time Secretary of State Marco Rubio said the US "welcomed" the deal before Trump described the plan in a post on Truth Social last month as "an act of great stupidity".
The comments came amid high tensions between the White House and European nations over the US President's desire to purchase Greenland from Denmark and his threats to impose tariffs on the UK and other nations that had backed Denmark.
The UK government said it would "never compromise on our national security", while at the time the prime minister's official spokesperson insisted the US still supported the move.
The talks set to take place next week will be held in the capital of Mauritius, Port Louis.
They will focus on "security co-operation" and "effective implementation of security arrangements" to ensure long-term success between the Mauritius government and the US, the US State Department has said.
The Chagos Islands - officially known as the British Indian Ocean Territory - are located about 5,799 miles (9,332km) south-east of the UK and about 1,250 miles north-east of Mauritius, in the Indian Ocean.
The islands have been under British control since 1814 and were bought by the government for £3m, which led to the establishment of the islands as an overseas territory in 1965.
But Mauritius has long argued that it was illegally forced to give the islands away as part of a deal to gain independence.