President Donald Trump once again claimed ownership of Greenland in a late-night Truth Social boast.

The post, at about 12:17 a.m. EDT Wednesday, described “Massive Oil, Gas, and Mineral Exploration” getting ready to begin in “our new and beautiful Greenland.” Greenland is a self-governing territory of Denmark, not a U.S. territory.

Trump’s message read in full:

“Massive Oil, Gas, and Mineral Exploration is getting ready to begin in our new and beautiful Greenland! There are Experts that are saying that the amount of easily available Oil is far greater than that of almost any land, anywhere in the World and, even more importantly, from a Security Purpose in the Defense and Offense of both the United States of America, and Europe, is second to none. Any future attack on the United States will have to come across Greenland, where our Defense will routinely knock down drones, missiles, or any other form of weapon not yet even conceived. It gives us time, location, and sightline, like nowhere else in the World! Thank you for your attention to this matter.”

Trump did not name the experts or say which exploration projects he meant.

Last month, Trump announced a security agreement with Denmark and Greenland, signed Sept. 22 at the United Nations, that expands the U.S. military presence on the island. Trump said it gives the United States “permanent control” over Greenland’s security. Danish Prime Minister Mette Frederiksen said the deal recognizes Danish sovereignty and Greenlanders’ right to self-determination. Danish and Greenlandic lawmakers must still ratify it, according to ABC News.