Stephen Miller stunned US allies and rattled NATO on Monday night after flatly declaring that Greenland 'should be part of the United States' - and insisting that no country would dare fight Washington over the Arctic territory's future.

In a combative appearance on CNN's The Lead with Jake Tapper, the White House deputy chief of staff and homeland security adviser brushed aside repeated questions about whether the United States might use military force to seize Greenland, currently governed by Denmark.

'Nobody's gonna fight the United States militarily over the future of Greenland,' Miller said on air, brushing aside repeated attempts to get him to explicitly rule out military action.  

Pressed directly on whether military intervention was off the table, Miller did not deny the possibility. Instead, he challenged Denmark's sovereignty over the island.

'What is the basis of their territorial claim?' Miller asked. 

'What is their basis of having Greenland as a colony of Denmark? The United States is the power of NATO. For the United States to secure the Arctic region, to protect and defend NATO and NATO interests, obviously, Greenland should be part of the United States, and so that's a conversation that we're going to have as a country.'

The extraordinary comments came after President Donald Trump again refused to rule out taking Greenland by force, deepening fears among European allies that the administration is prepared to redraw borders inside NATO in the name of US 'national security'.

Miller insisted that the idea of Greenland joining the United States is not a sudden escalation, despite the renewed attention surrounding it.

'The president has been clear for months now,' Miller told Tapper. 

'It has been the formal position of the US government since the beginning of this administration - frankly, going back into the previous Trump administration - that Greenland should be part of the United States.'

When Tapper noted that the issue had suddenly become urgent following a provocative social media post by Miller's wife, Katie Miller, the senior White House aide bristled.

'I know you're treating this as breaking news,' Miller said, 'but the president has been very clear about that.'

Asked again whether the United States would rule out using force against another NATO country to achieve that goal, Miller deflected.

'There's no need to even think or talk about this in the context that you're asking of a military operation,' he said.

The controversy erupted over the weekend after Katie Miller, a former Trump White House official and conservative media figure, posted an image of Greenland draped in an American flag with a single word beneath it: 'SOON.'

The post went viral and landed just after the US carried out a dramatic operation in Venezuela that resulted in the capture of that country's president, raising alarm among allies about Washington's willingness to redraw borders by force.

Trump then fueled the backlash by reiterating his long-held belief that Greenland is vital to US national security.

Denmark's response was swift and unusually blunt.

In nationally televised remarks, Danish Prime Minister Mette Frederiksen reminded viewers that Greenland has repeatedly rejected becoming part of the United States.

'I have already made it very clear where the Kingdom of Denmark stands and that Greenland has repeatedly said that it does not want to be part of the United States,' Frederiksen said.

She also issued a stark warning about the consequences of US aggression.

'If the US chooses to attack another NATO country militarily, then everything stops, including NATO and thus the security that has been established since the end of the Second World War,' Frederiksen said.

The prime minister later expanded on that message in her New Year's address, condemning what she described as escalating threats from Denmark's closest ally.

'Wanting to take over another country, other people, as if it were something you could buy and own - it doesn't belong anywhere,' Frederiksen said, according to the Danish newspaper Berlingske.

She added that Denmark is rapidly increasing military spending and Arctic defenses.

'We are in full swing strengthening Danish defense and preparedness,' she said. 'Never before have we increased our military strength so significantly. So quickly.'

Denmark's ambassador to the United States, Jesper Møller Sørensen, publicly rebuked the rhetoric after Katie Miller's post, reminding Washington of long-standing defense ties.

'Just a friendly reminder about the U.S. and the Kingdom of Denmark,' Sørensen wrote on X. 'We are close allies and should continue to work together as such. U.S. security is also Greenland's and Denmark's security.

'And yes, we expect full respect for the territorial integrity of the Kingdom of Denmark,' he added.

Despite repeated claims from Trump and his allies that the island is essential to US security, polling shows Greenlanders themselves overwhelmingly oppose becoming American.

According to a January 2025 survey by Verian, 85 per cent of Greenland’s roughly 57,000 residents said they do not want to join the United States. 

Only six per cent supported the idea, while nine per cent were undecided.

Greenland has had the legal right to declare independence from Denmark since 2009 but has not done so, largely because it relies on Danish financial support and public services.