In recent days, President Donald Trump has ratcheted up his pressure campaign to acquire Greenland, the Arctic island and semi-autonomous territory of NATO ally Denmark, citing U.S. national security needs, and has not ruled out taking it by military force over the heated objections of Greenlanders and the Danes.
On Saturday, in response to European allies coming to Greenland's defense and bolstering their military presence on the island, Trump threatened to impose 10% tariffs on Denmark, Norway, Sweden, France, the United Kingdom, the Netherlands, and Finland -- all U.S. allies -- starting on Feb. 1 and rising to 25% on June 1 if no deal is reached -- to stay in effect until the U.S. takes control of Greenland.
Greenland has strategic significance. In addition to its valuable minerals and massive oil and gas reserves, it is home to the U.S. Pituffik Space Base, the Defense Department's northernmost base, where about 150 American troops are stationed and which serves as a first line of defense against a missile attack over the Arctic.
The president, who says it is vital to his "Golden Dome" anti-missile concept, has argued the current U.S. presence there is insufficient to defend Greenland should Russia or China try to take over. He asserts neither Greenland nor the Europeans are capable of protecting it -- that only the U.S can keep it from Russian or Chinese encroachment.
"The United States needs Greenland for the purpose of National Security," Trump posted on social media on Friday. "It is vital for the Golden Dome that we are building. NATO should be leading the way for us to get it. IF WE DON'T, RUSSIA OR CHINA WILL, AND THAT IS NOT GOING TO HAPPEN!"
Asked how the Kremlin views Trump's statement that he intends to eliminate the Russian threat to Greenland, since Denmark has not done so, Kremlin spokesman Dmitri Peskov said, "There are international experts who believe that by resolving the issue of Greenland's accession, Trump will undoubtedly go down in history. And not only in the history of the United States but also in world history."
"Without discussing whether it is good or bad, it is difficult to disagree with these experts," he added.
Beijing said Trump should not use China as a "pretext."
"China's activities in the Arctic are aimed at promoting peace, stability and sustainable development in the region and are in accordance with international law," Chinese foreign ministry spokeswoman Mao Ning said last week. "The rights and freedoms of all countries to conduct activities in the Arctic in accordance with the law should be fully respected. The U.S. should not pursue its own interests by using other countries as a pretext."
Vice President JD Vance, who along with Secretary of State Marco Rubio met with Danish and Greenland officials in Washington last week, warned Europe about Trump's intentions.
"What we're asking our European friends to do is to take the security of that landmass more seriously because if they're not, the United States is gonna have to do something about it," Vance said earlier this month.
Danish officials have pushed back, pointing to a $6.5 billion Arctic defense package they announced last year as a sign they are willing to work with partners to defend Greenland from adversaries.
A treaty between the U.S. and Denmark, called the Defense of Greenland, was signed in April 1951 after World War II to allow the U.S. to increase its military presence without the territory coming under U.S. control. It was amended in 2004.
Even if he could purchase Greenland for the U.S., it's unclear how Trump intends to pay for the territory that Greenlanders have repeatedly said is not for sale.
"I'm not talking about money for Greenland yet. I might talk about that, but right now, we are going to do something on Greenland, whether they like it or not, because if we don't do it, Russia or China will take over Greenland, and we're not going to have Russia or China as a neighbor," the president said earlier this month.
The White House did not respond to an ABC News request for details on how the president planned to buy Greenland if there was such an opportunity.
The president has floated using revenue from his sweeping tariffs last year to fund a host of his policies, including sending dividend checks to middle- and low-income Americans. And if he planned to do the same with purchasing Greenland, he could run into a legal roadblock.
The Supreme Court is expected to decide soon whether the president's tariffs, which he issued through the International Emergency Economic Powers Act, were constitutional, putting in jeopardy the tens of billions in tariff revenue Customs and Border Protection said the U.S. took in last year. The U.S. could possibly be forced to refund that money.
The new tariffs the president is threatening to levy against the eight European nations could come under the same legal scrutiny. Treasury Secretary Scott Bessent on Sunday, asked what national emergency justifies them, defended the president's threat.
"The national emergency is avoiding a national emergency. That it is a strategic decision by the president; this is a geopolitical decision; and he is able to use the economic might of the U.S. to avoid a hot war," Bessent told NBC.
Those new proposed tariffs are already getting pushback from lawmakers. Democratic Senate Minority Leader Chuck Schumer on Saturday said his party will try to block those new tariffs.
"It is incredible that he wants to double down on the stupidity by imposing tariffs on our closest allies for his quixotic quest to take over Greenland," Schumer said in a statement. "Senate Democrats will introduce legislation to block these tariffs before they do further damage to the American economy and our allies in Europe."