Four countries have already vowed to provide Ukraine with F-16s, though Holubtsov believes that number could grow, as “almost every country that has F-16s in service are gradually replacing them with F-35s.” Read also: Dutch F-16 jets bound for Ukraine can strike Russia — Defense Minister “As for 30 planes, maybe 40. It should be understood here that not all planes transferred to Ukraine will now come to Ukraine,” he said. “Some will remain in those centers where our pilots and aviation personnel are trained. These will be the Ukrainian planes used to train our pilots.” “The should not surpris…