Officials from Denmark and Greenland met with several lawmakers on Capitol Hill this week as President Donald Trump reiterated his threats to take Greenland, possibly by force.

The meetings come as the Trump administration has repeatedly declined to rule out the possibility of using the U.S. military if diplomatic efforts to purchase the country do not succeed. Secretary of State Marco Rubio is set to meet with Danish officials next week to discuss a U.S. acquisition of Greenland, which is a territory of Denmark.

Danish Ambassador Jesper Møller Sørensen and Jacob Isbosethsen, the head of Greenland representation, met with a mix of Republican and Democratic House members and senators on Wednesday and Thursday — including Rep. Gregory Meeks, the highest ranking Democrat on the House Foreign Affairs Committee — in addition to briefing a group of bipartisan Hill staffers.

Sørensen and Isbosethsen “expressed an openness to discuss any measure that would enhance the security of the United States, while respecting the sovereignty of the Kingdom of Denmark” during a Tuesday meeting, Rep. Mike Flood (R-Neb.) said in a statement. He added that the meeting left him “confident that Secretary of State Marco Rubio can navigate a diplomatic win-win solution with one of our finest allies.”

Sens. Roger Wicker (R-Miss) and Jeanne Shaheen (D-N.H.) struck a different tone following a bipartisan meeting with the officials on Thursday morning.

“I think it’s been made clear from our Danish friends and from our friends in Greenland that that future does not include a negotiation,” Wicker told reporters after the meeting. “There’s no willingness on their part to negotiate for the purchase or the change in title to their land, which they’ve had for so long. That’s their prerogative and their right, and they’ve made that very clear to us”

Shaheen added that “there’s no reason for a negotiation around who controls Greenland, because Greenland, the United States and Denmark have been allies” for several decades.

Wicker — who told POLITICO on Tuesday that “this is a topic that should be dropped” — is one of several GOP lawmakers who have broken with the Trump administration’s push to acquire Greenland, including Republican Sens. Susan Collins of Maine, Thom Tillis of North Carolina and Mitch McConnell of Kentucky.

Isbosethsen reiterated on Thursday that “Greenland is not for sale,” a position that the territory’s leadership has repeatedly stood by in recent months as Trump has doubled down on his threats to purchase or take Greenland by force.

Trump’s increasingly forceful threats of possible U.S. intervention in countries like Greenland, Colombia and Cuba in the wake of the ouster of Venezuelan leader Nicolas Maduro have alarmed western allies, who worry that his efforts could destabilize NATO.

Eight European leaders threw their support behind Greenland in a joint statement released Tuesday, writing that “Security in the Arctic must therefore be achieved collectively, in conjunction with NATO allies including the United States, by upholding the principles of the UN Charter, including sovereignty, territorial integrity and the inviolability of borders.”

Polish Foreign Minister Radosław Sikorski also called on Congress to take a stance on Trump’s threats to seize Greenland on Wednesday, telling reporters, “The topic of territories, of war and peace, belongs to the U.S. Congress.”

Ambassadors from several NATO countries discussed taking steps to reinforce the organization’s Arctic flank at a closed-door meeting in Brussels on Thursday as concerns grow about the Trump administration’s insistence on taking Greenland by any means necessary.

Denmark, meanwhile, has no intention of rolling over, according to an EU diplomat with knowledge of the thinking in Copenhagen. While Denmark had until this week largely avoided officially raising the Greenland issue to the EU level to avoid inflaming the situation and giving credence to the idea that Trump could buy or annex Greenland, the government in Copenhagen has now changed its strategy in response to the most recent spate of U.S. rhetoric.

The Danish ambassador and the Greenlandic representative hope to hammer the message that Greenland does not want to become a part of the U.S. and that the rest of Europe has their backs, the diplomat said.

A spokesperson for Rep. Jason Crow (D-Colo.), who sits on the House Armed Services Committee, told POLITICO in a statement that he “reiterated his support for the people of Greenland’s sovereignty, and stressed their importance to the NATO alliance” during a Wednesday meeting with Sørensen and Isbosethsen.

The officials have several more meetings planned with lawmakers on Thursday afternoon and Friday.

Zoya Sheftalovich contributed to this report.