Ukraine has already deployed US-made F-16 fighter jets as part of its defense against Russia, Ukrainian President Volodymyr Zelenskyy said on Sunday.

Ukraine had pleaded with Western allies for the US-made fighter jets, the most sought-after item on the list of military hardware that Kyiv has requested from Western nations, more or less since the full-scale war began in 2022.

What did Zelenskyy say about the F-16s?

As the background for his address on Ukraine's Armed Forces Day, Zelenksyy appeared with two F-16 jets bearing Ukraine's trident insignia on their tails and draped in camouflage netting.

"F-16s are in Ukraine. We did it. I am proud of our guys who are mastering these jets and have already started using them for our country," he said.

Two more flew overhead as he was speaking in Kyiv.

"We often heard the word 'impossible'... Now it is a reality. Reality in our skies. F-16s in Ukraine. We made it happen."

However, the president added "the number of F-16s we have in Ukraine, the number of pilots who have already been trained, is not enough."

"The positive thing is that we are expecting additional F-16s... many guys are now training."

US and Lithuanian officials said on Wednesday that Ukraine had taken delivery of its first batch of F-16 multirole combat planes.

"This is the new stage of development of the air force of Ukraine's armed forces," Zelenskyy said.

"We did a lot for Ukrainian forces to transition to a new aviation standard, the Western combat aviation," he added, citing the need there had been for relentless diplomacy to obtain the jets.

"We often heard 'it is impossible' as an answer but we still made our ambition, our defensive need, possible," he said.

Western fighter pilots generally train for three years to learn how to fly and operate the complex jets on a course that has been condensed to roughly nine months for Ukrainian pilots in the US and Europe.

Pilots are among the most difficult military personnel to replace or retrain, especially at speed. 

What do the jets offer Ukraine?

The fighter jets, built by US arms manufacturer Lockheed Martin, have long been coveted by Kyiv due to their advanced offensive and defensive capabilities and availability, being a staple part of many Western militaries.

They are fitted with a 20-millimeter cannon and can be armed with bombs, rockets and missiles. It is unclear what sort of missiles the F-16s already deployed are carrying.

Short-range missiles would only allow Ukraine to carry out more defensive tasks and keep Russian aircraft in check over its territory.

Missiles with a longer range would allow them to attack Russian warplanes using guided bombs and therefore significantly reduce Russia's offensive opportunities.

Until now, Kyiv's forces have relied on an aging fleet of Soviet-era MiG-29 and Sukhoi warplanes that are outnumbered by Russia's fleet.

Several European countries that were once tied to the Soviet Union sent more of these planes, which Ukrainian pilots can already fly and engineers can service, to Kyiv. But as the war grinds on replacement parts in particular have become an issue, given that new ones are produced in Russia.

What happens now?

Ukraine is eventually expected to receive at least 79 F-16s from Belgium, Denmark, the Netherlands and Norway, with deliveries to continue in the coming years.

The United States won't be directly supplying Kyiv with F-16s from its own inventory, but President Joe Biden did give the green light for the US-built jets to be deployed in Ukraine.

In response to news that the planes had arrived in Ukraine, Kremlin spokesman Dmitry Peskov said they would not be a "magic pill" that changes the course of the conflict. He added that the Russian military had already offered rewards to personnel who destroy F-16s.

rc/msh (dpa, AP)