Denmark and Greenland’s top diplomats held high-stakes talks at the White House on Wednesday, with US President Donald Trump warning it was “vital” for the United States to take control of the Arctic island.

Shortly before the meeting with US Vice President JD Vance and Secretary of State Marco Rubio, Denmark announced it was immediately boosting its military presence in strategic Greenland.

Footage from CNN showed Danish Foreign Minister Lars Lokke Rasmussen and his Greenlandic counterpart Vivian Motzfeldt arriving at the White House campus, while AFP journalists saw Rubio and Vance heading into the talks.

Trump’s escalating threats over Greenland — a vast and sparsely populated autonomous territory belonging to Nato ally Denmark — have deeply shaken transatlantic relations.

The 79-year-old Republican insisted ahead of the talks that Nato should support the US effort to take control of Greenland, saying it was crucial for his planned Golden Dome air and missile defence system.

“Nato becomes far more formidable and effective with Greenland in the hands of the UNITED STATES. Anything less than that is unacceptable,” he wrote on his Truth Social network.

“IF WE DON’T, RUSSIA OR CHINA WILL, AND THAT IS NOT GOING TO HAPPEN!” added Trump.

Vance, who slammed Denmark as a “bad ally” during a visit to Greenland last year, is known for a hard edge, which was on display when he publicly berated Ukrainian President Volodymyr Zelensky in the Oval Office last February.

“If the US continues with, ‘We have to have Greenland at all costs,’ it could be a very short meeting,” said Penny Naas, a senior vice president at the German Marshall Fund of the United States, a Washington think tank.

Trump has derided recent Danish efforts to increase security for Greenland as amounting to “two dogsleds”. Denmark says it has invested almost $14 billion in Arctic security.

Danish Defence Minister Troels Lund Poulsen sought to further ease US concerns on Thursday, telling AFP his country was boosting its military presence in Greenland and was in talks with Nato allies.

The Danish defence ministry then announced that it would do so “from today,” hosting a military exercise and sending in “aircraft, vessels and soldiers”. Swedish officers were joining the exercise at Denmark’s request, Stockholm said.

‘Big problem’

Denmark’s Rasmussen said ahead of the meeting that he was hoping to “clear up certain misunderstandings”. But it remains to be seen if there is a chance of de-escalating the situation.

Greenland’s leader said on Tuesday that the island prefers to remain part of Denmark, prompting Trump to say “that’s going to be a big problem for him.” Shortly after the White House talks, a senior delegation from the US Congress — mostly Democrats, but with one Republican — will visit Copenhagen to offer solidarity.

Trump has appeared emboldened on Greenland — and on what he views as the US backyard as a whole — since ordering a deadly January 3 attack in Venezuela that removed President Nicolas Maduro.

The White House has said that military action against Greenland remains on the table. Danish Prime Minister Mette Frederiksen has warned that an attack on a Nato ally would end the alliance that has been the bedrock of Western security since World War II.

It is a founding member of Nato, and its military joined the United States in the wars in Afghanistan and Iraq, the latter to much criticism.

An agreement with Denmark currently allows the United States to station as many soldiers as it wants on Greenland. It also has a “space base” at Pituffik in northern Greenland.

Greenland’s Prime Minister Jens-Frederik Nielsen, meanwhile, said ahead of the Washington talks that “Greenland does not want to be part of the United States.” But Trump has been insistent that he wants to acquire Greenland wholesale, repeatedly insisting on what he calls the threat of a takeover by Russia or China.

The two rival powers have both stepped up activity in the Arctic, where ice is melting due to climate change, but neither claims Greenland, which is home to 57,000 people.