Keir Starmer last night confronted Donald Trump over his extraordinary threat to seize Greenland.

In an unprecedented rebuke amid warnings Nato was 'heading for disaster', he told the US President his proposal to impose tariffs on those willing to defend the island was 'wrong'.

The confrontation came after Western leaders warned Mr Trump he risked a 'dangerous downward spiral' in relations, adding that their new Arctic mission posed 'no threat to anyone'.

But a Cabinet minister dismissed demands for the UK to hit back by cancelling the King's planned state visit to America in the spring. 

As a deepening crisis threatens the future of Nato, European leaders are considering deploying their so-called trade 'bazooka' for the first time in retaliation, an economic tool that would hit the US with £81billion in tariffs.

The 'big bazooka' is an anti-coercion instrument adopted in 2023 to combat political blackmail. 

It allows the EU to restrict countries from participating in public tenders, limit trade licences and shut off access to the single market.

But there was no sign of the White House backing down, with one key figure blasting Europe as too weak to defend itself.

Last night a senior UK government figure told the Daily Mail: 'I have never seen anything like this. Our adversaries will be rubbing their hands with joy. We are heading towards a disaster.'

President Trump has long sought to obtain Greenland, a self-governing territory within the Kingdom of Denmark, to boost the US's security – believing it is at risk of invasion by China.

He has increasingly raised the prospect of military invasion – then at the weekend he turned against the European countries that have defended the huge island's independence.

On his Truth Social platform, the President declared that, from February 1, the US would impose a 10 per cent tariff on all exports from Denmark, Finland, France, Germany, the Netherlands, Norway, Sweden and the UK – increasing it to 25 per cent in June.

'This tariff will be due and payable until such time as a deal is reached for the complete and total purchase of Greenland.'

There was immediate condemnation from around the world, including across the political spectrum in Britain, where Sir Keir branded the proposals 'completely wrong'.

Yesterday he went further by giving his message directly to the President, who spent the weekend at his golf course in Florida.

A Downing Street spokesman said: 'The Prime Minister spoke to the prime minister of Denmark, Mette Frederiksen; president of the European Commission, Ursula von der Leyen; and Nato secretary general Mark Rutte. He then spoke to President Trump.

'In all his calls, the Prime Minister reiterated his position on Greenland. He said that security in the High North is a priority for all Nato allies in order to protect Euro-Atlantic interests.

'He also said that applying tariffs on allies for pursuing the collective security of Nato allies is wrong.' Sir Keir is expected to try to lobby Mr Trump in person at the Davos summit this week.

The eight countries facing the tariff hit – which experts fear could drive Britain into recession with a £6billion cost to exporters – issued a statement condemning Mr Trump's threats and defending a military exercise in Greenland that is thought to have angered him.

It said: 'As members of Nato, we are committed to strengthening Arctic security as a shared transatlantic interest. The pre-coordinated Danish exercise Arctic Endurance conducted with allies responds to this necessity. It poses no threat to anyone.

'We stand in full solidarity with the Kingdom of Denmark and the people of Greenland. Tariff threats undermine transatlantic relations and risk a dangerous downward spiral.'

Ms Frederiksen added: 'Europe will not be blackmailed. We want to co-operate and we are not the ones seeking conflict.'

But US Treasury Secretary Scott Bessent said: 'Europeans project weakness, US projects strength. 

'The President believes enhanced security is not possible without Greenland being part of the US.' 

Former head of the diplomatic service Lord McDonald told the BBC: 'If there were any kind of clash between the Americans and Europeans over Greenland, that would be the end of Nato. 

'There's no way back, when one ally turns against another militarily.'

Tory MP Simon Hoare said: 'The upcoming state visit of HM The King to the US must now be cancelled. 

'The civilised world can deal with Trump no longer. He is a gangster pirate.'

But Culture Secretary Lisa Nandy dismissed the idea, telling Sky News: 'It just sounds a bit childish because people's jobs and lives depend on us being able to have a serious conversation with our counterparts on either side of the Atlantic.'