The U.S. has allowed countries with F-16 fighter jets to deliver them to Ukraine, saying the announcement meets the demands of the conflict.

Nevertheless, training pilots and mechanics takes time and for the time being, only the Netherlands has shown its willingness to take the plunge. According to an initial assessment by the United States Air Force, it would take at least four months of intensive training for the best Ukrainian pilots to be operational. It may take even more to train mechanics, said Gen. Patrick Dutartre, former fighter pilot in the French Air Force.