A bipartisan group of U.S. lawmakers will visit Denmark this week as President Donald Trump threatens a takeover of Greenland, an autonomous territory of the Danish kingdom that hosts a U.S. airbase.

The delegation will be led by Democratic U.S. Senator Chris Coons and will include Republican U.S. Senator Thom Tillis and Democratic Senators Jeanne Shaheen and Dick Durbin, along with several members of the House of Representatives, Coons’ office said Monday.

Why it matters

Democratic and Republican lawmakers said last week they expect the U.S. Senate to eventually vote on legislation aimed at limiting Trump’s authority to attempt to seize Greenland from Denmark, a long-time U.S. ally.

Trump has repeatedly argued that Washington must own Greenland to prevent Russia or China from gaining control of the strategically located, mineral-rich Arctic territory. He has said that a U.S. military presence there is insufficient.

“One way or the other we are going to take Greenland,” Trump has said, while adding he would prefer to strike a deal with Denmark.

Greenland and Denmark have both insisted the territory is not for sale, but Trump has not ruled out the use of force. Denmark and the U.S., both NATO members, are scheduled to meet this week to discuss the issue.

“As co-chair of the Senate NATO Observer Group, I believe it is critical that Congress stands united in supporting our allies and respecting the sovereignty of Denmark and Greenland,” Tillis said.

Trump’s “continued threats toward Greenland are unnecessary and would only weaken our NATO alliance,” Durbin added.

Coons’ office said the delegation will be in Copenhagen on Friday and Saturday.

Competing bills

Republican U.S. Representative Randy Fine introduced legislation Monday titled the Greenland Annexation and Statehood Act, which would authorize Trump to annex Greenland if passed.

Democratic U.S. Representative Jimmy Gomez is preparing a competing measure, the Greenland Sovereignty Protection Act, which would bar federal funds from being used to support any effort by Trump to take over the territory.

Concerns over Trump’s remarks have intensified following a recent U.S. military operation abroad that underscored his willingness to use force, raising alarm among allies about the implications for NATO unity and international norms.