This is reported by The New York Times.
"Twelve pilots so far — fewer than a full squadron — are expected to be ready to fly F-16s in combat by this summer after 10 months of training in Denmark, the United Kingdom and the United States," the article says.
Read more: When Ukraine Will Receive the First Danish F-16 Fighter Jets Became Known
The New York Times highlighted that Ukrainian pilots are currently awaiting fighter jets and pilot instructors at a new training center at the Fătesti airbase in southern Romania, which is expected to play a crucial role in their training. However, it remains unclear when Ukrainian pilots will commence training at the center.
The New York Times also reported that Denmark, the Netherlands, Norway, and Belgium have committed to sending approximately 45 aircraft to Ukraine, sufficient for three small squadrons. Denmark is set to dispatch the initial six planes in late spring, with an additional 13 expected to arrive by the end of the year and in 2025.

The delay in F-16 deliveries is attributed to the extensive training required for Ukrainian pilots. Although the training of Ukrainian pilots is progressing rapidly compared to standard F-16 training, it is slower than Ukraine and its allies had hoped.
The delay in delivering the aircraft was also influenced by Washington's stance. The Biden administration emphasized that F-16 fighters were unlikely to be a decisive factor in the war.
“There aren’t very many Ukrainian pilots to be able to pilot those aircraft,” Jake Sullivan, the White House national security adviser, told defending the Biden administration’s delay in approving plans to send F-16s to the war.
The NYT also stated that the F-16 fighter jets would likely come armed with short- and medium-range missiles and bombs, partially making up for the shortage of ground-based munitions.
Officials have indicated that Western defense contractors will be responsible for accompanying the planes to Ukraine and remaining with them until a sufficient number of Ukrainian crews are available to ensure proper maintenance.
Presently, approximately 50 Ukrainian technicians are undergoing training in Denmark to acquire the skills needed for the maintenance and repair of the aircraft, along with expertise in handling the weapon systems.

Read more: The First Photo of F-16 Aircraft with Ukrainian Insignia Appears, Making russians Nervous