Davos, Jan. 20 -- European Commission President Ursula von der Leyen on Tuesday cautioned the United States against imposing punitive tariffs on allied European countries in connection with Greenland, calling such a move a "mistake".

"The proposed additional tariffs are a mistake especially between long-standing allies," von der Leyen told the gathering in Davos, Switzerland.

Underscoring the importance of credibility in transatlantic commitments, she said, "The European Union and the United States have agreed to a trade deal last July. And in politics as in business - a deal is a deal. And when friends shake hands, it must mean something," she said.

Von der Leyen also signalled that Europe would respond firmly to any further escalatio...