U.S. President Donald Trump has warned that he will fully implement tariffs on European countries opposing his plan to acquire Greenland. He announced that starting February 1, imports from the United Kingdom will face a 10 percent tariff, rising to 25 percent on June 1. The same tariffs will apply to seven NATO allies—Denmark, Norway, Sweden, France, Germany, the Netherlands, and Finland—until Denmark agrees to a deal for selling Greenland to the United States.

European nations have taken a united stance to defend Greenland’s sovereignty. Denmark’s Foreign Minister Lars Løkke Rasmussen said ownership cannot be claimed through threats, while the UK’s Foreign Minister Yvette Cooper stated that only Greenlanders and Denmark can decide Greenland’s future. NATO Secretary-General Mark Rutte affirmed that the alliance will continue working with Denmark and Greenland to ensure Arctic security.

The European Union’s foreign policy chief, Kaja Kallas, said the EU will not back down from its position and called an emergency meeting in Brussels on Thursday to coordinate responses. Denmark has warned that U.S. interference in Greenland could jeopardize NATO’s future.