US President Donald Trump wants to own Greenland. He has repeatedly said the United States must take control of the strategically located and mineral-rich island, which is a semiautonomous region that's part of NATO ally Denmark.

Greenland, the largest island on Earth, possesses some of the richest stores of natural resources anywhere in the world.

These include critical raw materials – resources such as lithium and rare earth elements (REEs) that are essential for green technologies, but whose production and sustainability are highly sensitive – plus other valuable minerals and metals, and a huge volume of hydrocarbons, including oil and gas.

Three of Greenland’s REE-bearing deposits, deep under the ice, may be among the world’s largest by volume, holding great potential for the manufacture of batteries and electrical components essential to the global energy transition.

Officials from Denmark, Greenland and the United States met Thursday in Washington and will meet again next week to discuss a renewed push by the White House, which is considering a range of options, including using military force, to acquire the island.

Trump said on Friday he is going to do “something on Greenland, whether they like it or not.”

If it's not done “the easy way, we're going to do it the hard way," he said without elaborating what that could entail. In an interview on Thursday, he told The New York Times that he wants to own Greenland because “ownership gives you things and elements that you can't get from just signing a document.”

Danish Prime Minister Mette Frederiksen has warned that an American takeover of Greenland would mark the end of NATO, and Greenlanders say they don't want to become part of the US.

This is a look at some of the ways the US could take control of Greenland and the potential challenges.

Greenland’s concentration of natural resource wealth is tied to its hugely varied geological history over the past 4 billion years. Some of the oldest rocks on Earth can be found here, as well as truck-sized lumps of native (not meteorite-derived) iron.

Diamond-bearing kimberlite “pipes” were discovered in the 1970s but have yet to be exploited, largely due to the logistical challenges of mining them.

Greenland was shaped by many prolonged periods of mountain building. These compressive forces broke up its crust, allowing gold, gems such as rubies, and graphite to be deposited in the faults and fractures. Graphite is crucial for the production of lithium batteries but remains “underexplored, according to the Geological Survey of Denmark and Greenland, relative to major producers such as China and South Korea.

But the greatest proportion of Greenland’s natural resources originates from its periods of rifting – including, most recently, the formation of the Atlantic Ocean from the beginning of the Jurassic Period just over 200 million years ago.

Greenland’s onshore sedimentary basins, such as the Jameson Land Basin, appear to hold the greatest potential of oil and gas reserves, analogous to Norway’s hydrocarbon-rich continental shelf. However, prohibitively high costs have limited commercial exploration.

There is also a growing body of research suggesting potentially extensive petroleum systems ringing the entirety of offshore Greenland.

Military action could alter global relations

Trump and his officials have indicated they want to control Greenland to enhance American security and explore business and mining deals. But Imran Bayoumi, an associate director at the Atlantic Council's Scowcroft Centre for Strategy and Security, said the sudden focus on Greenland is also the result of decades of neglect by several US presidents towards Washington's position in the Arctic.

The current fixation is partly down to “the realisation we need to increase our presence in the Arctic, and we don't yet have the right strategy or vision to do so,” he said.

If the US took control of Greenland by force, it would plunge NATO into a crisis, possibly an existential one.

While Greenland is the largest island in the world, it has a population of around 57,000 and doesn't have its own military. Defence is provided by Denmark, whose military is dwarfed by that of the US.

It's unclear how the remaining members of NATO would respond if the US decided to forcibly take control of the island or if they would come to Denmark's aid.

“If the United States chooses to attack another NATO country militarily, then everything stops,” Frederiksen has said.

Trump said he needs control of the island to guarantee American security, citing the threat from Russian and Chinese ships in the region, but “it's not true, said Lin Mortensgaard, an expert on the international politics of the Arctic at the Danish Institute for International Studies, or DIIS.

The US already has access to Greenland under a 1951 defence agreement, and Denmark and Greenland would be “quite happy” to accommodate a beefed-up American military presence, Mortensgaard said.

For that reason, “blowing up the NATO alliance” for something Trump has already, doesn't make sense, said Ulrik Pram Gad, an expert on Greenland at DIIS.

Bilateral agreements may assist the effort

US Secretary of State Marco Rubio told a select group of US lawmakers this week that it was the Republican administration's intention to eventually purchase Greenland, as opposed to using military force. Danish and Greenlandic officials have previously said the island isn't for sale.

It's not clear how much buying the island could cost, or if the US would be buying it from Denmark or Greenland.

Washington also could boost its military presence in Greenland “through cooperation and diplomacy,” without taking it over, Bayoumi said.

One option could be for the US to get a veto over security decisions made by the Greenlandic government, as it has in islands in the Pacific Ocean, Gad said.

Palau, Micronesia and the Marshall Islands have a Compact of Free Association, or COFA, with the US.

That would give Washington the right to operate military bases and make decisions about the islands' security in exchange for US security guarantees and around USD 7 billion of yearly economic assistance, according to the Congressional Research Service.

It's not clear how much that would improve upon Washington's current security strategy. The US already operates the remote Pituffik Space Base in northwestern Greenland, and can bring as many troops as it wants under existing agreements.

Influence operations expected to fail

Greenlandic politician Aaja Chemnitz told The Associated Press that Greenlanders want more rights, including independence, but don't want to become part of the US.

Gad suggested influence operations to persuade Greenlanders to join the US would likely fail. He said that it is because the community on the island is small and the language is “inaccessible.”

Danish Foreign Minister Lars Lokke Rasmussen summoned the top US official in Denmark in August to complain that “foreign actors” were seeking to influence the country's future. Danish media reported that at least three people with connections to Trump carried out covert influence operations in Greenland.

Even if the US managed to take control of Greenland, it would likely come with a large bill, Gad said. That's because Greenlanders currently have Danish citizenship and access to the Danish welfare system, including free health care and schooling.

To match that, “Trump would have to build a welfare state for Greenlanders that he doesn't want for his own citizens,” Gad said.

Disagreement unlikely to be resolved

Since 1945, the American military presence in Greenland has decreased from thousands of soldiers over 17 bases and installations to 200 at the remote Pituffik Space Base in the northwest of the island, Rasmussen said last year. The base supports missile warning, missile defence, and space surveillance operations for the US and NATO.

US Vice President JD Vance told Fox News on Thursday that Denmark has neglected its missile defence obligations in Greenland, but Mortensgaard said that it makes “little sense to criticise Denmark” because the main reason why the US operates the Pituffik base in the north of the island is to provide early detection of missiles.

The best outcome for Denmark would be to update the defence agreement, which allows the US to have a military presence on the island and have Trump sign it with a “gold-plated signature,” Gad said.

But he suggested that's unlikely because Greenland is “handy” to the US president.

When Trump wants to change the news agenda — including distracting from domestic political problems — “he can just say the word Greenland' and this starts all over again," Gad said.