• President-elect Donald Trump declined to rule out using the U.S. military to take control of the Panama Canal and Greenland.
• Trump has also expressed interest in making Canada the "51st State."
• Trump's eldest son, Donald Trump Jr., traveled to Greenland's capital, Nuuk, reportedly to create media content.

President-elect Donald Trump on Tuesday declined to rule out using the U.S. military to take control of the Panama Canal and Greenland, expanding on a spate of recent remarks he has made about acquiring more territory for the United States during his second term.

"We need them for economic security," Trump said of both the Central American trade route and the autonomous territory of Denmark, during a lengthy press conference at his Florida home, Mar-a-Lago.

A reporter asked Trump if he could assure the public that he would not use military or economic coercion in pursuit of either land.

"No, I can't assure you of either of those two," the president-elect replied.

"The Panama Canal was built for our military. I'm not going to commit to that, no ... It might be that you'll have to do something," he said.

Trump also expressed concern and frustration about China's activity in both the Panama Canal and Greenland, sending a possible signal to the powerful U.S. adversary about its own efforts to extend its global reach.

The canal is "being operated by China," he said. "We didn't give it to China, and they've abused it."

At the same press conference, Trump announced that his administration would seek to change the name of the Gulf of Mexico to the "Gulf of America."

"What a beautiful name. And it's appropriate," he said.

The petroleum-rich body of water is the world's ninth-largest, and has been identified on maps as the Gulf of Mexico since the 1500's.

Since winning the November presidential election, Trump has repeatedly mused about annexing territories, especially the Panama Canal. He has criticized former President Jimmy Carter, who died on Dec. 29, for negotiating the treaty that ultimately gave Panama full control of the 51-mile waterway.

The Republican, who takes office in less than two weeks, has also expressed interest in making Canada the "51st State."

But he said Tuesday that he was considering using only economic, and not military, pressure toward the U.S. ally and major trading partner.

"That would really be something," he said of absorbing Canada into the United States. "You get rid of that artificially drawn line, and you take a look at what that looks like, and it would also be much better for national security."

Trump complained about the U.S. trade deficit with Canada, saying, "That's okay to have if you're a state, but if you're another country, we don't want to have it."

Trump has threatened to impose large tariffs on imports from Canada, the second-largest trading partner with the U.S.

But "there would be no Tariffs" on Canada if it became a U.S. state, Trump said in a Truth Social post Monday. He posted that comment after embattled Canadian Prime Minister Justin Trudeau announced he will step down as the country's leader.

Trump's expansionist comments have at times been met with ridicule.

Ontario Premier Doug Ford on Monday jokingly issued a counter-offer for Canada to buy Alaska and other U.S. states before concluding, "It's not realistic."

And Trudeau wrote on X on Tuesday afternoon, "There isn't a snowball's chance in hell that Canada would become part of the United States."

Greenland's prime minister, Mute Egede, flatly said in December that the island is "not for sale and will never be for sale."

Trump's eldest son, Donald Trump Jr., landed in Greenland's capital, Nuuk, on Tuesday, reportedly to create media content.

His father, in a Truth Social post the previous day, said Trump Jr. was there to "visit some of the most magnificent areas and sights."

"Greenland is an incredible place, and the people will benefit tremendously if, and when, it becomes part of our Nation," Trump wrote.