Former U.S. President Donald Trump has criticized UK Labour leader Sir Keir Starmer over the decision to transfer sovereignty of the Chagos Islands to Mauritius, a move that has thrown the agreement into uncertainty.

In a fiery message posted on Truth Social, Trump expressed his concerns to the UK Prime Minister, labeling the British government’s agreement regarding the strategic Indian Ocean territory as a ‘big mistake.’

Trump cautioned against relinquishing control of the vital joint US-UK military base located on Diego Garcia, the largest of the Chagos Islands. This base operates under a controversial long-term lease with Mauritius, a nation allied with China.

Additionally, Trump suggested that the U.S. military might need to conduct operations against Iran from Diego Garcia if Tehran fails to negotiate with him.

This outspoken critique emerged shortly after the U.S. State Department publicly supported the UK’s decision to proceed with the agreement with Mauritius concerning the Chagos archipelago.

U.S. officials are scheduled to engage in discussions next week in Port Louis, Mauritius, to address the ‘effective implementation of security arrangements for the base.’ However, Trump’s comments on Truth Social indicate he may desire revisions to the terms established by the Labour government.

It will likely force the Government to further postpone debate in Parliament on the bill to ratify the treaty, under which the UK will also hand Mauritius as much as £30billion, and could even lead to another major U-turn.

The legislation was delayed last month when President Trump first stunned ministers by describing the agreement as a ‘great act of stupidity’.

A group of Chagos islanders land on the archipelago to establish a permanent settlement, more than 50 years after the population was evicted from the British colony

Donald Trump has lashed out at Sir Keir Starmer for making a ‘big mistake’ over the Chagos Islands deal

In his new message, he wrote: ‘I have been telling Prime Minister Keir Starmer, of the United Kingdom, that Leases are no good when it comes to Countries, and that he is making a big mistake by entering a 100 Year Lease with whoever it is that is ‘claiming’ Right, Title, and Interest to Diego Garcia, strategically located in the Indian Ocean.

‘Our relationship with the United Kingdom is a strong and powerful one, and it has been for many years, but Prime Minister Starmer is losing control of this important Island by claims of entities never known of before. In our opinion, they are fictitious in nature.’

He went on: ‘Should Iran decide not to make a Deal, it may be necessary for the United States to use Diego Garcia, and the Airfield located in Fairford, in order to eradicate a potential attack by a highly unstable and dangerous Regime — An attack that would potentially be made on the United Kingdom, as well as other friendly Countries.

‘Prime Minister Starmer should not lose control, for any reason, of Diego Garcia, by entering a tenuous, at best, 100 Year Lease.’

And he added: ‘We will always be ready, willing, and able to fight for the U.K., but they have to remain strong in the face of Wokeism, and other problems put before them. DO NOT GIVE AWAY DIEGO GARCIA!’

Tonight, Shadow Foreign Secretary Dame Priti Patel said: ‘President Trump has once again publicly rebuked Keir Starmer and his Government over their ill-judged, unnecessary and expensive Chagos Surrender. This is an utter humiliation for Starmer.

‘It’s time Starmer finally saw sense, u-turned and scrapped this appalling deal altogether. Giving up British sovereign territory to an ally of China and paying for the privilege is irresponsible and reckless and is clearly undermining our relationship with our most important ally.’

Tory peer Lord Kempsell, who has lobbied the White House to intervene, said: ‘Starmer’s deal is finished. He must now withdraw his Diego Garcia Bill from Parliament.’

Reform MP Andrew Rosindell said: ‘It speaks volumes when POTUS appears more concerned with defending the United Kingdom’s national interest than Keir Starmer.

‘The Government must do the patriotic, honourable, and common-sense thing and scrap this disgraceful sell-out of a deal. Keep Chagos British.’

And former minister Lord Redwood said: ‘Good advice from President Trump on Chagos. Please listen Prime Minister.’

Trump’s comments come after the Mail revealed a close friend of Sir Keir Starmer shared an £8million pot for his work in negotiating the ‘surrender’ deal.

Philippe Sands KC, who describes himself as a ‘great friend’ of the Prime Minister, pocketed his share of the sum while acting as chief legal counsel to Mauritius between 2010 and 2024.

In that time he secured the controversial deal which will see Britain hand back sovereignty of the strategically important archipelago, also known as the British Indian Ocean Territory, and lease the Diego Garcia military base for 99 years – at an average cost of £101m a year.

Professor Sands, a leading international human rights lawyer who is also close with Attorney General Lord Hermer, led a series of legal teams who were almost exclusively tasked with fighting for the cession of the island to Mauritius.

Together they were allocated at least £8,300,000 from the Mauritian state budget, official documents show.

While the exact figure Professor Sands took home is unknown, his role as chief counsel will have seen him earn the largest cut, according to one international lawyer, who said a large bonus could also be paid on the deal’s completion.

Asked how much he was paid, Sands told a House of Lords Committee he ‘did not know’ but admitted he was ‘remunerated, as I am for almost all my cases. It was not done pro bono’.

This is a breaking news story- more to follow