President Trump on Friday said he may impose tariffs on countries that do not support the U.S. taking control of Greenland, a semi-autonomous Danish territory.

During a White House event about rural healthcare, Trump recounted how he had threatened European allies with tariffs on pharmaceuticals, accordding to the Associated Press.

“I may do that for Greenland too,” Trump said. “I may put a tariff on countries if they don’t go along with Greenland, because we need Greenland for national security. So I may do that.”

Vice President JD Vance and Secretary of State Marco Rubio met with the foreign ministers of Denmark and Greenland in Washington, D.C., earlier this week. The meeting resulted in an agreement to set up a working group, but Denmark and the White House then offered sharply diverging public views on its purpose.

European leaders have insisted that only Denmark and Greenland can decide who controls the territory, and Denmark said this week that it was increasing its military presence in Greenland in cooperation with allies.