LONDON (AP) — British Prime Minister Keir Starmer said Monday that U.S. President Donald Trump’s threat of tariffs against allies over Greenland is “completely wrong” and a trade war is in no one’s interest.

Trump said Saturday that he would charge a 10% import tax starting in February on goods from eight European nations, including the U.K., because of their opposition to American control of Greenland, setting up a potentially dangerous test of U.S. partnerships in Europe. Greenland is a semiautonomous territory of NATO ally Denmark.

The president indicated the tariffs were retaliation for last week’s deployment of symbolic numbers of troops from the European countries to Greenland, which he has said was essential for the “Golden Dome” missile defense system for the U.S. He also has argued that Russia and China might try to take over the island.

Starmer said Britain supports the “fundamental right” of Greenland and Denmark to decide the future of the Arctic island.

Starmer, who has worked to force a strong relationship with Trump, said the U.K.-U.S. relationship was vital and “we are determined to keep that relationship strong, constructive and focused on results.” But he said that doesn’t mean pretending differences don’t exist.

He said at a news conference in London that “being pragmatic does not mean being passive and partnership does not mean abandoning principles.” But seeking to calm the turmoil, Starmer said Britain will work with allies in Europe, NATO and the United States and “keep dialogue open.”

He indicated that Britain is not planning to consider retaliatory tariffs. “We have not got to that stage. My focus is on making sure we don’t get to that stage,” he said.