Here are five things to know about Greenland:

- 'Green land' -

Inhabited by Inuits on and off for almost 4,500 years, the island was originally dubbed 'Green land' by Erik the Red, a Viking explorer who landed on the far southern edge of the island in the 10th century.

That was a less-than-fitting name, since around 80 percent of its more than two million-square-kilometre (772,204 square-mile) surface is covered by ice.

Colonised by Denmark 300 years ago, it was integrated into the Kingdom of Denmark in 1953.

In 1979, Copenhagen granted Greenland home rule and its autonomy was further extended in a 2009 law, though Copenhagen still decides on foreign policy and military matters.

The economy, based primarily on the fisheries industry, is heavily dependent on subsidies from Copenhagen of more than $565 million a year, equivalent to a fifth of the island's GDP.

Contrary to Denmark, Greenland is not a member of the European Union after withdrawing in 1985, three decades before Brexit. More than 90 percent of its 57,000 inhabitants -- around 19,000 of whom live in the capital Nuuk -- are Inuits.

- Coveted by US -

President Donald Trump has repeatedly stated since December that the United States plans to take over Greenland, raising his tone in a March 4 speech to Congress.

"We need it really for international world security. And I think we're going to get it," he said.

US interest in the territory is not new: In the 1823 Monroe Doctrine, the United States claimed Greenland was part of its "sphere of interests".

Almost a century later, in 1917, Washington acquired the Virgin Islands from Denmark and recognised Denmark's sovereignty over Greenland.

During World War II, when Denmark was occupied by Germany, Greenland came under US protection and was returned to Denmark at the end of the war.

The US maintained several large military bases; One of them, Pituffik -- in the island's northwest -- is still in use.

The United States also has a consulate in Nuuk.

- Minerals in spades -

Greenland's soil is rich in untapped mineral and oil reserves, but on a global scale the amounts are modest.

And there are currently only two mines in operation.

Greenland's rare earths -- demand for which is expected to surge in the future -- are estimated at 36.1 billion tonnes by the Geological Survey of Denmark and Greenland (GEUS).

But its rare earths reserves -- those that are economically and technically recoverable -- amount to only about 1.5 million tonnes, according to the latest report from the US Geological Survey (USGS).

Public opposition to uranium mining in southern Greenland has also led to legislation banning any mining of radioactive materials.

The island is also believed to be sitting on an abundance of oil and gas but has suspended exploration out of concern for the climate and aims to develop hydropower instead.

Melting glaciers are also releasing a mineral-rich rock flour that can be used as a fertiliser in depleted or arid soil in Africa and South America.

- Front line of global warming -

The massive territory is experiencing firsthand the effects of global warming, with the Arctic heating up four times faster than the rest of the planet since 1979, according to a study in US journal Nature.

Numerous studies have also shown that the melting of Greenland's ice sheet has picked up speed.

If the ice mass, the second largest in the world after Antarctica, were to melt completely it could cause sea levels to rise by more than seven metres (23 feet), according to simulations.

- Northern routes -

Greenland lacks a road or rail network, so people rely on helicopters, planes and boats to get around.

Rising temperatures and melting ice are meanwhile opening new and shorter shipping routes, reinforcing the territory's strategic position.

It is counting on growing tourism to boost its economy.

In November, the Nuuk airport opened to long-haul flights, making international access to the territory easier. Twice weekly direct flights to New York are due to start this summer.