French President Emmanuel Macron on Sunday denounced US President Donald Trump’s threat to annex Greenland, saying “that’s not what allies do,” as he made a historic trip to the Danish autonomous region.

Macron’s visit to Nuuk, the capital of Greenland, was the first by a foreign head of state since Trump rekindled his bid to buy the strategically important, resource-rich island. Trump has used national security as a justification and has refused to rule out using force to obtain Greenland. Denmark has steadfastly insisted the territory “is not for sale.

The trip was designed to reassert “France’s and the EU’s solidarity” with Greenland’s independence, the French president said. He was greeted warmly by Danish Prime Minister Mette Frederiksen and Greenlandic Prime Minister Jens-Frederik Nielsen, and by throngs of people brandishing red-and-white Greenlandic flags.

Negotiations on a Danish frigate launched the six-hour visit, which was followed by helicopter ride and hike along melting glacier at Mount Nunatarsuaq, where Macron saw for himself the impact of climate change. The Arctic, warming four times the global rate, is opening up new shipping routes and speeding the scramble for rare earth materials.

Macron’s visit was at the invitation of Danish and Greenland officials, a far cry from US Vice-President JD Vance’s March visit, which was widely regarded as provocative. On that visit, Vance condemned Denmark for abandoning Greenland’s security, further exacerbating tensions.

The Pituffik US military base on Greenland is a central part of Washington’s missile defense network, located on a crucial transit route between Russia and North America.

Although most of Greenland’s 57,000 people are in favor of independence from Denmark, they reject US rule. Macron’s visit also highlighted scientific cooperation, with France promising further investment in Arctic ecosystem science, following in the footsteps of explorer Paul-Emile Victor.

Macron will travel next to Canada for the G7 summit.