BRITAIN would have first refusal to buy Greenland and potentially scupper Donald Trump’s plot to acquire the nation.

Only a week into his second term, Trump has sent Denmark into “crisis mode” by insisting the US will take Greenland over.

The president wants to put the Danish territory under US control – vowing to do so to protect global “national security and freedom”.

But a pact made more than a century ago could be a major roadblock to Trump‘s land grab.

Determined Trump would have to go through the UK first – and get Sir Keir Starmer’s approval.

Tom Høyem, who was Copenhagen’s last permanent representative in the Arctic territory, pointed out an agreement signed back in 1917.

The undertaking – rubber-stamped after America first made a tentative attempt to acquire the land – is still valid.

Høyem told The Sunday Times: “If Trump tried to buy Greenland, he would have to ask London first.

“The United Kingdom demanded in 1917 that if Greenland were to be sold then the UK should have the first right to buy it.”

The agreement was made because Canada was a British dominion at the time and lies just a few miles from Greenland.

It comes as the Danes were left in “crisis mode” after an explosive 45-minute phone call between Trump and Denmark‘s Prime Minister.

Trump has been piling the pressure on Mette Frederiksen after first floating takeover plans before his second term in The White House.

Despite reportedly being told to “f*** off” by the Danes, the President continued his claims on the ice island.

Trump said on Saturday: “I don’t really know what claim Denmark has to it, but it would be a very unfriendly act if they didn’t allow that to happen because it’s for the protection of the free world.

“I think Greenland we’ll get because it has to do with freedom of the world.

“It has nothing to do with the United States other than that we’re the one that can provide the freedom. They can’t.”

Frederiksen had insisted Greenland is not for sale or up for grabs.

The pair had a fiery phone call last week, according to the Financial Times.

Conversations between the leaders have turned sour despite Frederiksen agreeing to be more co-operative with army bases and mining.

Several European officials revealed the reported hostility in last week’s phone call.

One official said: “The intent was very clear. They want it.

“The Danes are now in crisis mode.”

As an autonomous territory of Denmark, Greenland has its own ruling body – but people from the island have Danish citizenship.

But Denmark is responsible for Greenland’s protection and their army would be the army to mobilise against the Americans.

Its defence budget is around £6billion – 100 times smaller than the eye-watering £750billion America splashes on defence.

Despite the two nations continuing to squabble over ownership of Greenland, PM Egede has made it clear that Greenland wants to be completely independent – both of Denmark and a lurking America.