"If we spend extra money for defence on products off the shelf from the USA, we are cementing our dependence on others," Michael Schoellhorn, the head of Airbus Defence and Space, said in an interview with Germany's Augsburger Allgemeine newspaper.

"The Danes are seeing right now that this might not be such a great idea, if they ever needed to defend Greenland with their American F-35 jets," he added.

US President Donald Trump has indicated his designs on the territory of NATO ally Denmark, telling Congress on Tuesday that the US would secure Greenland "one way or the other."

That and other suggestions that European security is no longer a priority for the US, including moves to open direct talks with Russia over an end to the war in Ukraine, have prompted a renewed focus on defence from European governments.

Germany's likely next chancellor Friedrich Merz announced plans Tuesday to partially exempt defence funds from rules that limit new government debt, paving the way for a dramatic boost in military spending in Europe's largest economy.

Schoellhorn said Germany needed to "realise that Europe is under threat and too weak in this new era of history -- both economically and militarily".

Listed in Frankfurt, Paris and Madrid, Airbus is known for making commercial passenger jets.

Its defence division manufacturers aircraft including the Eurofighter Typhoon jet and C295 transport aircraft.