President Donald Trump has warned that the U.S. could use military force to secure the Diego Garcia air base in the Chagos Islands if any future deal threatens access to the joint U.S.-U.K. installation.

Trump made the comments Thursday in a Truth Social post while also signaling his willingness to move past tensions with British Prime Minister Keir Starmer after what he described as ‘very productive discussions’ about the Indian Ocean base.

Emphasizing the base’s strategic importance, Trump said the role of Diego Garcia was essential to U.S. national security.

‘It is the site of a major U.S. military base, strategically situated in the middle of the Indian Ocean and, therefore, of great importance to the national security of the United States,’ Trump wrote.

Trump also acknowledged that the U.K. struck what he called ‘the best deal he could make’ under a controversial agreement to transfer sovereignty of the islands to Mauritius while leasing Diego Garcia back for at least 99 years.

‘However, if the lease deal, sometime in the future, ever falls apart, or anyone threatens or endangers U.S. operations and forces at our base, I retain the right to militarily secure and reinforce the American presence in Diego Garcia,’ Trump warned.

‘Let it be known that I will never allow our presence on a base as important as this to ever be undermined or threatened by fake claims or environmental nonsense.’

The comments marked a slight shift in tone from Trump, who in January criticized the U.K.-Mauritius deal as an ‘act of great stupidity’ and an ‘act of total weakness,’ accusing Britain of surrendering a critical military asset.

Diego Garcia serves as a hub for long-range bombers, logistics, intelligence collection and military communications across the Middle East, the Indo-Pacific and Africa, hosting around 2,500 U.S. and military and civilian personnel.

The island base has been used for long-range U.S. operations such as in Afghanistan and in Yemen.

According to Reuters, Downing Street had confirmed Trump and Starmer discussed Diego Garcia during a recent call and agreed to safeguard the base’s continued operation.

‘Turning to Diego Garcia, and the deal the U.K. has secured to maintain control of the U.S.-U.K. military base to protect national security, the leaders recognized its strategic importance,’ a No. 10 spokeswoman said.

‘The leaders agreed their governments would continue working closely to guarantee the future operation of the base and speak again soon.’

Under the agreement, British taxpayers are projected to pay roughly £35 billion [$47 billion] over the next century, including annual payments of about £160 million [$216 million] to Mauritius, according to public estimates.

Britain has also agreed to approximately £3 billion [$4 billion] in compensation over the life of the deal, with an option to extend the lease for an additional 50 years.

The agreement has also drawn criticism from Britain’s Conservative Party, which argues the deal weakens the U.K.’s strategic position and risks undermining long-standing security ties with the U.S.

Mauritius has said its sovereignty over the islands is ‘unequivocally recognized’ under international law and has called for swift implementation of the agreement.

As previously reported by Fox News Digital, a Downing Street spokesperson also said in January the U.K. is continuing efforts to ‘allay any concerns’ in Washington.

‘We will continue to engage with the U.S. on this important matter and the importance of the deal to secure U.S. and U.K. interests,’ the spokesperson said. 

Fox News Digital has reached out to the White House and Downing Street for comment.