The first four Ukrainian pilots plan to complete training on F-16 fighter jets by the summer, CNN said, citing data from the Arizona National Guard.

It is noted that the pilots began training in the middle of October with the 162nd Fighter Wing in Tucson, Arizona. The Pentagon said the training process will take several months.

A second group of another four pilots began training in January, while a third group of four pilots is currently going through English-language training required for a fourth pilot to fly, according to Captain Erin Hannigan, a spokeswoman for the Arizona National Guard.

All of the pilots are expected to complete training between May and August, although the exact timeline depends on the progress of the program.

Last summer, a coalition of countries led by Denmark began training Ukrainian pilots on American aircraft. The Netherlands, Denmark and Norway have pledged to provide Ukraine with F-16 fighter jets following a training program. The United States has also pledged to approve the transfer of aircraft immediately upon completion of training.