Keir Starmer sets out his position on Greenland in late-night call with Donald Trump

During the call, Sir Keir and President Trump also discussed the seizure of the Russian-flagged oil tanker Marinera earlier in the day, continuing negotiations on the future of Ukraine and US military action in Venezuela.

It is the first time the pair have spoken since US special forces seized Venezuelan president Nicolas Maduro and brought him to New York on Saturday.

Britain's position on the High North was first formally outlined in a European joint statement on Tuesday.

The UK, Denmark, France, Germany, Italy, Spain and Poland all vowed that "Greenland belongs to its people. It is for Denmark and Greenland, and them only, to decide on matters concerning Denmark and Greenland".

Then, speaking at Prime Minister's Questions on Wednesday, Sir Keir said: "The future of Greenland is for Greenland and the Kingdom of Denmark alone."

Greenland and Denmark have both insisted the island is not for sale.

President Trump has in recent days repeated he wants to gain control of Greenland, an idea he has voiced since 2019 during his first presidency.

He argues the island is key to US military strategy and claims Denmark has not done enough to protect it.

Greenland boasts thousands on thousands of square miles of land in the Arctic Circle.

It also sits between two major Arctic shipping routes - which are vital for Russian trade - and forms one third of the "GIUK Gap", a key strategic waterway between itself, Iceland and the UK.

If the US military were to seize Greenland from longtime ally and Nato colleague Denmark, it would doubtless send shockwaves through the Nato alliance and could deepen the divide between President Trump and Europe.

White House spokeswoman Karoline Leavitt however said that President Trump remains committed to Nato - even as he and his national security team are holding active discussions about a US purchase of Greenland.

Mr Trump said on social media that the US "will always be there for Nato, even if they won't be there for us".

On the other side of the north Atlantic on Wednesday, Danish officials issued a veiled threat to the States over the Arctic island.

Denmark could "shoot first and ask questions later" if the US follows through on its threats to invade according to a decades-old military rule.

The Danish defence ministry confirmed the existence of the long-standing rule, which says soldiers would "immediately" launch a counter-attack "without seeking orders".

One senior European official has piled pressure on Copenhagen to lead the way in coordinating a response.

But "the Danes have yet to communicate to their European allies what kind of concrete support they wish to receive", the official revealed.