Pentagon Press Secretary John Kirby explained on Tuesday that US allies have aided Ukraine in bolstering its fleet of fighter aircraft.

Although Washington has not provided Kiev with some of the Soviet-type weaponry it requested, countries with compatible gear in their arsenal have sent it, according to Kirby.

“They have received support to get some of their fixed-wing aircraft more operable again,” Kirby told reporters, adding that Ukraine currently has more fixed-wing fighter aircraft than they did two weeks ago.

"That’s not by accident. That’s because other nations who have experience with those kinds of aircraft have been able to help them get more aircraft up and running."

Pentagon's spokesperson didn't disclose which countries were involved in the shipments, nor did he specify the number of jets that were repaired and put back into service.

The aid currently being sent to Ukraine, such as artillery pieces, radar systems and coastal defense systems, are tailored to the battles expected in Donbass, according to Kirby.

Ukraine has also received more tanks, he added. 

“The kinds of tanks they know how to use are not the tanks that we have in our inventory, but other nations have provided some tanks,” Kirby said. “Some nations have provided spare parts, so that they can get their inoperable tanks operable again.”