WEST PALM BEACH, Fla. — First it was Canada, then the Panama Canal. Now Donald Trump again wants Greenland.

The president-elect is renewing unsuccessful calls he made during his first term for the U.S. to buy Greenland from Denmark, adding to the list of allied countries with which he’s picking fights even before taking office on Jan. 20.

In a Sunday announcement naming his ambassador to Denmark, Trump wrote: “For purposes of National Security and Freedom throughout the World, the United States of America feels that the ownership and control of Greenland is an absolute necessity.”

Trump again having designs on Greenland comes after he suggested over the weekend that the U.S. could retake control of the Panama Canal if something isn’t done to ease rising shipping costs required for using the waterway linking the Atlantic and Pacific oceans.

He’s also been suggesting that Canada become the 51st U.S. state and referred to Prime Minister Justin Trudeau as “governor” of the “Great State of Canada.”

Stephen Farnsworth, a political science professor at the University of Mary Washington in Fredericksburg, Virginia, said Trump tweaking friendly countries harkens back to an aggressive style he used during his days in business.

“You ask something unreasonable and it’s more likely you can get something less unreasonable,” said Farnsworth, who is also author of the book “Presidential Communication and Character.”

Greenland, the world’s largest island, sits between the Atlantic and Arctic oceans. It is 80% covered by an ice sheet and is home to a large U.S. military base. It gained home rule from Denmark in 1979, and its head of government, Múte Bourup Egede, suggested that Trump’s latest calls for U.S. control would be as meaningless as those made in his first term.

“Greenland is ours. We are not for sale and will never be for sale,” he said. “We must not lose our years-long fight for freedom.”

Trump canceled a 2019 visit to Denmark after his offer to buy Greenland was rejected by Copenhagen.

He also suggested Sunday that the U.S. is getting “ripped off” at the Panama Canal.

“If the principles, both moral and legal, of this magnanimous gesture of giving are not followed, then we will demand that the Panama Canal be returned to the United States of America, in full, quickly and without question,” he said.

Panama President José Raúl Mulino responded in a video that “every square meter of the canal belongs to Panama and will continue to,” but Trump fired back on his social media site: “We’ll see about that!”

The United States built the canal in the early 1900s but relinquished control to Panama on Dec. 31, 1999, under a treaty signed in 1977 by President Jimmy Carter.

The canal depends on reservoirs that were hit by 2023 droughts that forced it to substantially reduce the number of daily slots for crossing ships. With fewer ships, administrators also increased the fees that shippers are charged to reserve slots to use the canal.