NUUK, Greenland (AP) — Denmark’s prime minister has told the U.S. during a visit to Greenland that “you cannot annex another country,” even with the argument that international security is at stake.

U.S. Secretary of State Marco Rubio, meanwhile, said on Friday that Washington will respect Greenland’s self-determination and Copenhagen “should focus on the fact that the Greenlanders don’t want to be a part of Denmark.”

Danish Prime Minister Mette Frederiksen was wrapping up a three-day visit to the strategically critical Arctic island on Friday as U.S. President Donald Trump seeks control of Greenland. He argues that Greenland, a semiautonomous territory belonging to the Kingdom of Denmark, is critical to U.S. security.

A week ago, Vice President JD Vance visited a remote U.S. military base in Greenland and accused Denmark of underinvesting in the territory.

Frederiksen pushed back against the U.S. criticism as she spoke on Thursday alongside Greenland’s incoming and outgoing leaders on board a Danish naval ship. She argued that Denmark, a NATO ally, has been a reliable friend.

Speaking in English, she said that “if we let ourselves be divided as allies, then we do our foes a favor. And I will do everything that I can to prevent that from happening.”

“When you ask our businesses to invest in the U.S., they do. When you ask us to spend more on our defense, we do; and when you ask of us to strengthen security in the Arctic, we are on the same page,” she said.

“But when you demand to take over a part of the Kingdom of Denmark’s territory, when we are met by pressure and by threats from our closest ally, what are we to believe in about the country that we have admired for so many years?”

“This is about the world order that we have built together across the Atlantic over generations: you cannot annex another country, not even with an argument about international security,” Frederiksen said.

The Danish leader said that, if the U.S. wants to strengthen security in the Arctic, “let us do so together.”

Political parties in Greenland, which has been leaning toward eventual independence from Denmark for years, last week agreed to form a broad-based new coalition government in the face of Trump’s designs on the territory. Those have angered many in Greenland and Denmark.

In an interview with Newsmax on Thursday, Vance repeated the accusation that Denmark has “really underinvested in the infrastructure and security of Greenland.”

He said Trump’s point is that “this matters to our security, this matters to our missile defense, and we’re going to protect America’s interests come hell or high water.”

Danish Foreign Minister Lars Løkke Rasmussen, who was attending a meeting in Brussels with his NATO counterparts, wrote on social network X that he had an “honest and direct” meeting Thursday with Rubio.

“I made it crystal clear that claims and statements about annexing Greenland are not only unacceptable and disrespectful,” Løkke Rasmussen wrote. “They amount to a violation of international law.”

Rubio told reporters in Brussels Friday that “no one’s annexed anything.” He added that Vance has made clear that “he’s going to respect the self-determination of Greenlanders.”

“Denmark should focus on the fact that the Greenlanders don’t want to be a part of Denmark,” Rubio said.

“We didn’t give them that idea. They’ve been talking about that for a long time,” he said. “Whenever they make that decision, they’ll make that decision.”

“If they make that decision, then the United States would stand ready, potentially, to step in and say, okay, we can create a partnership with you,” Rubio said, adding that “we’re not at that stage.”