"If it comes to it, it is most likely something that NATO is going to get involved in," Bauer said during a Washington Post interview.
"So, in that sense, I think it is extremely important before anything like that would happen, is that there is a discussion among political leaders in the [NATO] alliance."
Earlier, French President Emmanuel Macron told a French TV channel that Paris will transfer Mirage 2000-5 fighter jets to Kiev and train Ukrainian pilots. Macron also said that France plans to train 4,500 Ukrainian soldiers, but does not consider this decision to be an "escalation."
Ukrainian Commander-in-Chief Oleksandr Syrsky said that he had signed a permit for French instructors to visit training centers in Ukraine, welcoming "France's initiative to send instructors to Ukraine to train Ukrainian servicemen."