President Donald Trump has issued a renewed threat to impose tariffs on countries that oppose his effort to gain control over Greenland, escalating rhetoric as a U.S. congressional delegation visits Denmark following diplomatic talks in Washington earlier this week.

Speaking at the White House on Friday (Jan. 16), Trump said tariffs could be used against nations unwilling to agree on Greenland, arguing that the territory is vital to U.S. national security, though he did not specify which countries could be targeted.

Trump has increasingly relied on his broad tariff agenda as leverage to extract economic concessions and align foreign governments with U.S. policy priorities. Greenland has now become part of that strategy, after earlier threats to impose tariffs on countries trading with Iran.

At the same time, U.S. senators and representatives met with Danish lawmakers. Senator Lisa Murkowski of Alaska emerged as one of the strongest critics of Trump’s ambitions, emphasizing that most Americans oppose acquiring Greenland and view it as a partner rather than a possession.

The visit followed a series of meetings in Washington involving Danish and Greenlandic officials and members of Congress. Denmark and Greenland are seeking congressional backing to constrain potential White House actions, given Congress’s authority over federal spending.

Although the United States, Denmark, and Greenland remain deadlocked over the island’s future, officials agreed this week to establish a working group to manage the diplomatic dispute. Trump has repeatedly insisted that U.S. control of Greenland is essential for national security, a position firmly rejected by both Denmark and Greenland.

Meanwhile, Denmark has invited NATO allies to participate in military exercises in Greenland, with several European countries already deploying personnel. Danish officials said the drills are meant to address regional security concerns, not to counter possible U.S. aggression.

Large-scale protests are expected in Copenhagen and other Danish cities, as well as in Nuuk, reflecting public opposition to Trump’s stance. In Washington, lawmakers have introduced legislation aimed at preventing the use of U.S. funds to occupy or annex NATO member territory without consent.

Although Trump could veto the bill, Congress retains the power to restrict federal funding. Supporters argue the measure demonstrates bipartisan commitment to NATO and respect for Greenland’s sovereignty.

European countries have also stepped up their military presence in Greenland, underscoring the urgency with which they view U.S. statements. Greenland, a semi-autonomous territory within the Kingdom of Denmark, is protected under NATO’s collective defense provisions and European Union solidarity clauses.

While mainstream Republicans continue to support the transatlantic alliance, few are willing to openly challenge Trump. Senior figures have warned that pursuing control of Greenland could undermine trust with allies and risk damaging U.S. strategic interests worldwide.