() Trump’s calls to buy Greenland are about one thing, according to Bill O’Reilly, lithium. He says the Trump administration wants to reduce its dependence on China.

“Lithium is the No. 1 product (China mines),” O’Reilly said on “On Balance.” “Under the permafrost, in Greenland, is a lot of lithium. That’s what this is about.”

O’Reilly’s comments come as Trump has shown a renewed interest in annexing Greenland over the last few weeks.

“The United States is not going to invade Greenland. … We’ll have an advantage over China. That’s what it’s about,” O’Reilly said.” “They’re not going to let us do anything. That will be part of the deal to protect our investment.”

What presence does the US have in Greenland now?

The U.S. military maintains a permanent presence at the Pituffik air base in Greenland’s northwest.

A 1951 agreement between the United States and Denmark established the United States’ right to construct military bases in Greenland and move forces freely on its territory as long as Denmark and Greenland are notified.

Historically, Denmark has accommodated the U.S. military in Greenland because Copenhagen does not have the capability to defend the vast island itself, and because of U.S. security guarantees to Denmark through the NATO alliance, said Kristian Soeby Kristensen, senior researcher at Copenhagen University’s Centre for Military Studies.

What is Greenland’s current status?

Greenland has been controlled by Denmark for centuries, previously as a colony and now as a semi-sovereign territory under the Danish realm. It is subject to the Danish constitution, meaning any change to its legal status would require a constitutional amendment.

In 2009, the island was granted broad self-governing autonomy, including the right to declare independence from Denmark through a referendum.

Prime Minister Mute Egede, who has stepped up a push for independence, has repeatedly said the island is not for sale and that it is up to its people to decide their future.

Decades ago, the U.S. under then-President Harry Truman sought to buy the island as a strategic asset during the Cold War for $100 million in gold, but Copenhagen declined to sell.

Trump offered to buy it during his first term in 2019 but both Greenland and Denmark rejected the proposal.