Donald Trump has sparked a fresh row with Denmark after appointing a special envoy to Greenland, the vast Arctic island he has said he would like to annex.

In response to a question from the BBC about the new role of Jeff Landry, the Republican governor of Louisiana, Trump said the US needed Greenland for “national protection” and that “we have to have it”.

Landry, he said, would “lead the charge” as special envoy to Greenland, a semi-autonomous part of the Kingdom of Denmark.

The move has angered Copenhagen, which said it would call the US ambassador for “an explanation”. Greenland’s prime minister said the island must “decide our own future” and its “territorial integrity must be respected”.

Gov Landry said in a post on X that it was an honour to serve in a “volunteer position to make Greenland a part of the US”.

Since returning to the White House in January, Trump has revived his long-standing interest in Greenland, citing its strategic location and mineral wealth.

He has refused to rule out using force to secure control of the island, a stance that has shocked Denmark, a Nato ally that has traditionally enjoyed close relations with Washington.

“We’ll have to work that out,” Trump added. “We need Greenland for national security, not minerals.”

Trump specifically mentioned Chinese and Russian ships as potential threats in the nearby seas.

Greenland, home to about 57,000 people, has had extensive self-government since 1979, though defence and foreign policy remain in Danish hands. While most Greenlanders favour eventual independence from Denmark, opinion polls show overwhelming opposition to becoming part of the US.

Denmark’s Foreign Minister, Lars Lokke Rasmussen, described the appointment of Landry as “deeply upsetting” and warned Washington to respect Danish sovereignty.

He told Danish broadcaster TV2: “As long as we have a kingdom consisting of Denmark, the Faroe Islands and Greenland, we cannot accept actions that undermine our territorial integrity.”

Greenland’s Prime Minister, Jens-Frederik Nielsen, said the territory was willing to cooperate with the US and other countries, but only on the basis of mutual respect.

He said: “The appointment of a special envoy does not change anything for us. We decide our own future. Greenland belongs to Greenlanders, and territorial integrity must be respected.”

EU Commission President Ursula von der Leyen said in a post on X that the EU stands in “full solidarity with Denmark and the people of Greenland”.

Writing on social media earlier, the US president said Landry understood how “essential Greenland is to our national security” and would advance US interests.

The significance of this appointment is both the US presumption that Greenland is separate to Denmark and the new appointee’s assertion that he will help the island become part of the US.

Envoys are informal appointments and unlike official diplomats, do not have to be approved by the host country.

What this appointment shows is that Trump’s ambition to control Greenland remains undimmed.

As with his military and rhetorical aggression towards Venezuela, it indicates Trump is determined to gain greater control over what his recent National Security Strategy called “the Western hemisphere”, a sphere of influence that he hopes will cover the whole of the Americas.

Trump tried to buy Greenland during his first presidential term. Both Denmark and the Greenlandic government rejected the 2019 proposal, saying: “Greenland is not for sale.”

Landry has previously voiced his opinion on Greenland, writing on his personal X account in January: “President Donald J. Trump is absolutely right! We need to ensure that Greenland joins the United States. GREAT for them, GREAT for us! Let’s get it done!”

Landry is a military veteran and former police officer who was a US Congressman and Louisiana’s attorney general before being elected governor in 2023. He said his new role would not affect his duties as governor.

The dispute over his appointment comes as strategic competition in the Arctic grows, with melting ice opening new shipping routes and increasing access to valuable mineral resources.

Greenland is located in the Arctic between North America and Europe, which also makes it central to US and Nato security planning.

The US has maintained a base in Greenland since World War Two, after invading to establish military and radio stations across the territory after the Nazis occupied Denmark during the conflict.

Vice-President JD Vance visited the base in March as he asked Greenland’s people to “cut a deal with the US”.

The US reopened a consulate in Nuuk, the capital of Greenland, in 2020 – during Trump’s first term – after closing it in 1953. A number of European countries, as well as Canada, have honorary general consulates in Greenland.

Additional reporting by Bernd Debusmann Jr in Mar-a-Lago