US President Donald Trump's designs on Greenland, an autonomous Danish territory, have deeply shaken transatlantic relations.

When asked about the prospect of a US attack, Danish Defence Minister Troels Lund Poulsen called it a "very hypothetical question".

"I consider it unlikely that a NATO country would attack another NATO country," he said.

Denmark said earlier Wednesday it was bolstering its military presence in Greenland, "comprising aircraft, vessels and soldiers, including from NATO allies".

Sweden announced that it was sending officers to Greenland in response to a Danish request.

"Several of our partners and NATO allies will be going to Greenland, either as early as this evening or in the coming days," Lund Poulsen said, adding that it would be up to each country to communicate about its presence.

Trump has repeatedly insisted that he wants to acquire Greenland wholesale due to what he calls the threat of a takeover by Russia or China.

In a bid to find a way out of the crisis, Danish Foreign Minister Lars Lokke Rasmussen and his Greenlandic counterpart Vivian Motzfeldt arrived for White House talks with US Vice President JD Vance and Secretary of State Marco Rubio on Wednesday.