In July, the Ukrainian Armed Forces will receive only the first six F-16 fighters, The New York Times reports.
A total of about 45 units were promised, but their delivery and pilot training proved more difficult than expected.
The publication writes that the planes are ready, flight instructors are waiting for them at a new training center in Romania, created to train Ukrainian pilots, but they have not yet arrived. And it is unclear when their training will begin, which has created "confusion and chaos" in the delivery process.
But this does not mean that Ukrainian pilots are not being trained. Currently, twelve pilots - less than a full squadron - are expected to be ready to fly the F-16 in combat by this summer after 10 months of training in Denmark, the UK and the US.
The training process has been slowed by the language barrier and the study of Western flight technology.
The next group of eight Ukrainian pilots is due to arrive in Denmark at the end of the summer, but it is unclear when they will start training in Romania.
"It depends on the governments and contracts that support all this. We're still waiting for all the approvals," said Colonel Bill Thomas, a retired US Air Force officer who oversees Lockheed Martin's training program for Romanian pilots at Fătesti.
Denmark will send the first six fighters in late spring, with 13 more to arrive by the end of the year and in 2025. Other countries have not set delivery dates for their F-16s.
Another issue is the maintenance and repair of the aircraft. About 50 Ukrainian technicians are currently being trained in Denmark. One F-16 requires eight to 14 people to maintain. Officials told the NYT that Western defense contractors will have to escort the planes to Ukraine and stay with them until there are enough Ukrainian crews to properly maintain them - which could take years.
And the need to repair Ukraine's outdated and war-damaged runways could further delay the F-16's entry into the war.
