Donald Trump proclaimed on Wednesday that massive oil, gas and mineral exploration was set to begin in “our new and beautiful Greenland”, doing little to soothe tensions around the U.S.’s unyielding claims to the mineral-rich island.

Writing on Truth Social, the U.S. president boasted that Greenland held more easily available oil than almost anywhere else in the world, following an international controversy over a U.S. firm’s ‘unauthorised’ plans to start drilling on the territory’s east coast.

Trump also insisted on the strategic value of the Arctic island to the U.S., arguing: “Any future attack on the United States will have to come across Greenland, where our Defense will routinely knock down drones, missiles, or any other form of weapon not yet even conceived.

“It gives us time, location, and sightline, like nowhere else in the World!” he said.

The U.S., Denmark and Greenland last month signed an agreement expanding the US military’s role in Greenland and paving the way for two new military bases and Trump’s ‘Golden Dome’ missile defence system.

Under the deal, Washington would be allowed to establish new bases at Mestersvig, in eastern Greenland, and Narsarsuaq, in the south, potentially marking the first US military expansion on the vast Arctic island in decades.

Crucially, Mestersvig oversees the stretch of ocean between Greenland, Iceland and Britain – known as the GIUK gap – that Russia’s Northern Fleet must cross to reach the Atlantic. For Nato, controlling this chokepoint is critical to containing Russian naval power.

Vast energy and mineral reserves could also draw in big business, with Texas-based oil company Greenland Energy vying to drill this winter at an untested basin just south of Mestervig.

But Greenland’s island government in August issued a “strong warning” that no approval had yet been granted for the firm’s drilling materials to be brought ashore via the eastern coast. Authorities later forced the firm to delay drilling until next winter at the earliest.

The September agreement with Greenland was aimed at ending tensions after Trump’s repeated threats to take control of the island created friction with Washington’s allies in Europe.

It is still subject to a second reading in parliament before being put to a vote, with lawmakers expected to pass the legislation despite some opponents questioning the deal’s economic value to the territory.

“The US is granted extensive rights in our country. The people of Greenland are not guaranteed any fixed payment for those rights,” the chair of opposition party Naleraq, Pele Broberg, said in a parliamentary debate in Greenland’s capital Nuuk on Monday.

Former foreign minister Vivian Motzfeldt of the governing coalition’s Demokraatit argued that Greenland had secured “massive” protection from the U.S. without having to pay for it, while winning recognition as an autonomous nation.

The comments reflect a shift in tone from January, when the Danish defence ministry was warning that troops would be required to “immediately take up the fight” if Greenland was invaded, as the U.S. refused to rule out taking military action to seize the island.