UK's Chagos Treaty Is Stuck Until Trump Agrees
British officials believe the UK-Mauritius treaty on the Chagos Islands is on hold as long as Donald Trump opposes it. Trump told Andy Burnham the three-way plan was "a terrible deal" during talks at the UN General Assembly. The assessment, reported on 23 September, leaves a signed deal over sovereignty waiting for Washington's approval. The Guardian
Trump and Burnham held their first in-person meeting at the UN in New York on Tuesday, 22 September 2026. Trump said of the Chagos arrangement: "I don't support it. I think it's terrible". In the same meeting, Trump said he can do business with Burnham. BBC
Burnham said he had inherited the Chagos situation from Keir Starmer. He told Trump the UK will work to find a resolution. He said he was confident the UK could find a solution to revive the deal. London has since confirmed a review. Burnham said the UK will review the Chagos deal after Trump criticised it as terrible. Euronews
The UK government has made clear that Washington's approval is required. Defence secretary Wes Streeting said the deal as currently written cannot go ahead without American support. Streeting said payments worth at least £120m to Mauritius are on hold.
Those payments are central to the treaty. The UK signed a treaty last year to transfer sovereignty, or legal ownership, of the Chagos Islands to Mauritius. Under the treaty, the UK would keep control of the joint UK-US military base on Diego Garcia under a 99-year lease, essentially a long-term rental. Mauritius was set to receive £165m for three years and £120m a year from the fourth year.
The legal paperwork has kept moving while politics stalled. The UK/Mauritius Agreement concerning the Chagos Archipelago including Diego Garcia was published as CS Mauritius No.1/2025 on 1 September 2026. The UK government also published guidance on citizenship rights for Chagossians following the entry into force of the Diego Garcia treaty.
The diplomatic plan began under Rishi Sunak and has already shifted several times with Washington. In January, Trump called the UK plan to hand the islands to Mauritius an "act of great stupidity", while No. 10 said it would press ahead despite the criticism. Starmer then argued US intelligence agencies disagree with Trump's opposition. In February, Trump softened his criticism after a call with Starmer and later signed off on the handover. On 11 April 2026, the UK government said it had put on hold its deal to cede sovereignty after U.S. opposition, with Trump having previously described the arrangement as "a big mistake". Reuters
Starmer defended the agreement because international legal rulings had cast doubt on Britain's claim to the islands. Neil Kinnock said Burnham is right to review the deal following criticism from Trump. Sky News
The broader context here is a negotiation where ownership, base rights and money cannot be separated. The working limit is not the treaty text but the US position on Diego Garcia. Without American support, London cannot operate the 99-year lease. Without the lease, there is no political case in London for the payment package. That explains why Streeting linked the £120m payments directly to Washington.
Looking at what this means for the review, the options are narrow. A renegotiation would need to satisfy Trump without reopening the sovereignty bargain with Mauritius or undermining the command paper already published. Burnham's language points to adaptation rather than abandonment. He inherited the file, he has expressed confidence in a solution, and he has kept the channel to Trump open. Whether adaptation is possible depends on what Trump finds terrible: price, duration, sovereignty principle, or leverage over a new British leader. None of that has been stated in public.
In my view, the history urges caution about reading any single Trump statement as final. Criticism in January gave way to sign-off in February, then to renewed opposition by April and September. For Mauritius, the pause in payments creates pressure but also reason to wait. For the UK, the review buys time at the UN General Assembly moment without forcing a parliamentary fight over a treaty that cannot be carried out while Washington withholds consent.
