Germany emphasized that changing borders by force violates international law, while France stressed that the European Union does not accept threats directed at its "sovereign borders," according to the German news site Deutsche Welle on Wednesday.
For his part, German government spokesman Steffen Hebestreit stated that "the established principle is that borders should not be changed by force," referring to international agreements such as the United Nations Charter.
Hebestreit declined to comment on how seriously the German government takes Trump's statements, simply noting that the government has "taken note" of them.
Meanwhile, French Foreign Minister Jean-Yves Le Drian stated that Trump "should not threaten the sovereign borders of the European Union."
Le Drian added in radio remarks: "There is no room for the European Union to allow any country, no matter what, to violate its sovereign borders," emphasizing that Europe is a "strong continent."
He also pointed out that the world is witnessing a return of the "law of the strongest," but he stressed the importance of respecting European sovereignty.