Accordingly, senior members of Mr Trump’s administration fear that handing control of the water to China-allied Mauritius would open the door to espionage by sea.
Officials have in recent months highlighted the Chagos Islands’ importance, stressing top-secret capabilities.
Ben Judah, David Lammy’s former special advisor when he was foreign secretary, told The Telegraph this year: “This airbase…has super secret, super sensitive facilities there which are so important to what Britain is able to do in the world.
“The moment you understand what it is, you come into the British deep state’s logic, which is that we must retain access to this thing at all costs. We would never be able to replicate if we had to do it all by ourselves.”
A price for the Chagos Islands has not yet been discussed. Britain initially planned to give the islands to Mauritius and then pay around £35bn ($46.7bn) for 99 years to lease back the military base.
To take control of the islands, Washington would first have to allow Sir Keir’s deal to go through, then negotiate with the Mauritians once sovereignty had been transferred.
The president initially supported Sir Keir’s deal to give the islands away, but then chose to scuttle it after Sir Keir refused to allow the US to use Diego Garcia to carry out strikes on Iran in the opening hours of the war.
Labour had hoped to pass a bill to give the islands to Mauritius in 2025, but it cannot ratify the deal and hand the islands over to Mauritius without US consent.
In several public outbursts earlier this year, the president denounced the deal as an act of weakness and “great stupidity” and argued that Sir Keir is “losing control of this important island”, referring to Diego Garcia.