Ukrainian President Volodymyr Zelensky called on European leaders to provide his country with aircraft and long-range weapons to strengthen Kyiv's defenses against Russia.

Zelensky said while he was in Brussels to attend a summit of European Union leaders that several Western countries are ready to support his country with combat aircraft. No confirmation of these offers has been issued yet.

Here are some details about the fighters Ukraine wants, and what it might get:

What combat aircraft does Ukraine want?

Ukraine has been calling on its allies to send modern fighters, which Zelensky described in a speech to British lawmakers this week as "wings for freedom", to replace its aging fleet of Soviet MiGs and Sukhoi jets.

The wish list includes the American-made F-16 because of its destructive power and global availability, as well as the Swedish Gripen fighters, and says at the same time that it is still looking for other fighters that allies can provide it with.

Ukraine relies on its existing fleet to attack Russian positions and carry out interceptor flights, but its air force believes that providing newer fighters would change the course of the war.

Ukrainian officials stated that such aircraft would lead to "closing the skies" to Russian attacks, and that they would "contribute to the destruction of practically any target" in the air or on the ground.

When can Ukraine start using it?

Britain says Ukrainian pilots will need years to train to operate the new fighter models after Zelensky ordered the Eurofighter Typhoons.

As a first step, London agreed to start training pilots in the spring, and said it would consider reducing training courses for experienced Ukrainian pilots.

Britain has not committed any of its own Typhoon fighters, and says Ukrainian pilots may be trained to fly Western planes after the war ends.

Defense Secretary Ben Wallace said Britain would also need the approval of the other countries that make the Eurofighter - Germany, Italy and Spain - to send it.

Justin Pronk of the Royal United Services Institute believes supplying Typhoons to Ukraine would be a "very extravagant symbolic gesture".

Pronk said in an analysis that the Typhoon is equipped to fly at high altitudes to extend the range of its missiles, a tactic that Russia's long-range force would be able to largely negate.

He said that the "Typhoon" and "F-16" aircraft also need to take off from paved runways and central bases, while the Swedish Gripen can fly at lower altitudes and maintain them on shorter and more rugged runways.

Will Ukraine get combat aircraft?

Ukraine is confident that this will happen, and points to previous incidents in which the allies were initially reluctant to send advanced weapons, but later backed down.

The United States and France say they do not rule out sending fighter jets, although Germany does.

Swedish Prime Minister Ulf Kristersson did not object to sending fighter jets, but lowered expectations and said the issue was not on Stockholm's agenda at the moment.

Poland, a staunch supporter of Ukraine, said it would not make such a decision alone and that NATO needed to act collectively.

Slovakia has agreed to send 11 MiG fighter jets to Ukraine to bolster its existing fleet.

Western governments fear a decline in their defenses if they transfer a lot of their equipment, and they have so far avoided sending any weapons capable of striking deep into Russian territory so as not to give Moscow an excuse to escalate the war.