James Whitfield
James Whitfield Political analyst and journalist

Chagos Islands deal: why the UK is pausing it

The sovereignty transfer agreement for the Chagos Islands was already controversial before Donald Trump weighed in. On 22 September, in a conversation with UK Prime Minister Andy Burnham, Trump said he did not support it and called it a terrible deal. By 23 September, Defence Minister Wes Streeting had confirmed that without US backing the arrangement cannot go ahead, and payments to Mauritius were on hold. This is the second time in 2026 the process has been paused.

99year base lease proposed for Diego Garcia
£101mestimated annual payment (one figure in sources)
£165mpayment for first 3 years (separate figure in sources)
2times paused in 2026

What the transfer involves

Chagos Islands UK transfer: what was agreed and with whom

The agreement, negotiated under the previous government and carried into the Starmer administration, would transfer sovereignty of the British Indian Ocean Territory, including the Chagos Islands, to Mauritius. In exchange, the UK and US would retain the right to operate the Diego Garcia military base for 99 years under a lease arrangement. Diego Garcia is one of the most strategically important Western military installations in the Indian Ocean, used for logistics, surveillance, and long-range operations by both the US Air Force and the Royal Navy.

The financial terms have been reported differently in different sources, and the gap is significant enough to put both figures on the table rather than pick one as authoritative.

£101m–£165m
The range of annual payment figures reported for the Chagos transfer depending on which phase of the agreement is being measured. Sources differ and neither figure has been officially confirmed as final.

The cost question

How much does the UK pay Mauritius for Chagos? What the sources say

FigureWhat it coversSource type
£101m per yearAnnual average across the lease termReported figure, UK media
£165m per yearFirst three years of the agreementSeparate reporting, UK media
£120m per yearYears 4 onwards, some sourcesSeparate reporting, UK media
99 yearsLength of proposed Diego Garcia leaseBoth governments; reported widely

Source: UK media reporting on HM Government and Mauritius government negotiations; figures differ across sources and no single official figure has been published. Both are reproduced here as reported.

Why the figures differ The UK government did not publish a full breakdown of the financial terms when the agreement was announced. Different media outlets have reported different numbers based on different briefings. We are not choosing between them; both are in the table above.

Trump’s objection

Why Trump called the Chagos transfer terrible

Trump’s stated position is that the agreement gives away a strategic military asset for a payment he considers excessive. His concern is framed around Diego Garcia specifically, which the US uses as a key installation in the region. He told Burnham directly that he does not support the arrangement and the word “terrible” was reported across US and UK outlets. The White House has not offered a detailed alternative.

I don’t support it. I think it’s a terrible deal.
Donald Trump, on the Chagos Islands deal, speaking to Andy Burnham, 22 September 2026 · Source: press reports, Reuters, BBC

This is not the first time US pressure has caused the process to stall. In April 2026, when Trump first signalled that Washington was withdrawing support, London paused the talks then too. The pattern is the same: the UK government says it wants the agreement but cannot advance it without Washington’s backing, because Diego Garcia is a jointly operated facility.


The base question

Does the UK still control Diego Garcia?

For now, yes. The treaty has not been ratified, which means the sovereignty transfer has not taken place. Diego Garcia remains British Indian Ocean Territory and the facility continues to operate as before. If the transfer were completed, Mauritius would hold sovereignty over the islands, but the UK and US would retain operational control of the installation under the 99-year lease.

The question of the Chagossian community, the people displaced from the islands decades ago, is separate. Their right of return to the islands, other than Diego Garcia itself, is one of the elements of the negotiation but has not been central to the current pause.

Dato clave The transfer cannot proceed without US agreement because Diego Garcia is a jointly operated facility. Defence Minister Wes Streeting said on 23 September that without US support, the arrangement “can’t go ahead”. The installation remains operational and under British sovereignty while the process is paused.

Where things stand

British Indian Ocean Territory: current status

QuestionCurrent answer
Is the agreement in place?Negotiated but not ratified; on pause
Is Diego Garcia still British?Yes, sovereignty unchanged while process is paused
Are payments going to Mauritius?No, payments on hold
Does the US support the transfer?No; Trump called it a terrible deal on 22 September
Has this happened before?Yes, talks were also paused in April 2026
Is the treaty ratified?No

Source: Wes Streeting statement, 23 September 2026; Trump–Burnham call reports, 22 September 2026; HM Government statements


People also ask

Chagos Islands deal: frequently asked questions

How much does the UK pay Mauritius for Chagos?

Different sources report different figures. One set of reports puts the annual payment at around £101m averaged across the lease. Other reporting cites £165m for the first three years and £120m after that. The UK government has not published a single confirmed breakdown. Both figures are in circulation and both appear above.

Why did Trump oppose the Chagos arrangement?

Trump told Andy Burnham on 22 September that he considered it a terrible deal. His objection centres on Diego Garcia, a major US and UK military installation which he sees as too valuable to place under Mauritius sovereignty, even with a 99-year lease guarantee. He was not the first US figure to criticise the arrangement: opposition in Washington had already caused an earlier pause in April 2026.

Does the UK still own the Chagos Islands?

Yes. The treaty has not been ratified, so sovereignty has not transferred. The islands remain British Indian Ocean Territory. If and when a final accord is completed and ratified, Mauritius would receive sovereignty while the UK and US retain the facility under lease.

Is the Chagos treaty ratified?

No. The agreement was negotiated but not ratified, and is currently on pause for the second time in 2026 following Trump’s withdrawal of US support. For the latest position, Defence Minister Wes Streeting’s 23 September statement remains the most recent official word.

What about the Chagos islanders’ right of return?

The right of Chagossians to return to islands other than Diego Garcia is part of the broader negotiation. It has not been the central issue in the current pause, which is primarily about the base and the financial terms.

James Whitfield
James Whitfield
Political analyst and journalist

James Whitfield is a political analyst and journalist covering British and international affairs. He studied Politics and International Relations at the University of Edinburgh before spending eight years reporting from Westminster for regional and national outlets. His work focuses on electoral trends, party strategy and the intersection of domestic policy with global events. James has contributed analysis to broadcast panels and political podcasts across the UK media landscape. He is based in London and writes regularly for ukpolitical.info.

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