British Prime Minister Keir Starmer spoke by telephone with U.S. President Donald Trump on Saturday, with both leaders agreeing on the imperative to strengthen security in the Arctic as geopolitical competition intensifies and climatic changes reshape the region.

The Downing Street statement described Arctic security as an “absolute priority” for the UK government and underscored the importance of robust cooperation among international partners to address strategic challenges in the High North.

The conversation took place against the backdrop of heightened diplomatic focus on Greenland, where earlier tensions over U.S. tariff threats and Trump’s controversial proposals to acquire the territory had tested relations between London and Washington.

Starmer reiterated his commitment to collective defence and stressed that decisions about territorial sovereignty must respect the rights of local populations and allied agreements.

In addition to Arctic security, the leaders discussed ongoing efforts to secure a sustainable ceasefire in Ukraine and reaffirmed the necessity of continued support for Kyiv as it defends against Russia’s full-scale invasion.

Both sides emphasised the enduring strength of the UK-U.S. partnership and the need to maintain unity within the North Atlantic Treaty Organization as they face evolving global security dynamics.

The call reflects a shared recognition that adversarial actions by other powers, particularly in high-latitude regions, require coordinated strategic responses and sustained diplomatic engagement to protect Euro-Atlantic interests and uphold stability in an era of shifting geopolitical pressures.