The United States and its allies are beginning to consider training Ukrainian pilots as part of a long-term effort to potentially help Kiev build a future Ukrainian air force, Air Force Chief of Staff General Charles "CQ" Brown told Reuters.

Ukraine wants to buy U.S. fighter jets and train its pilots. The Ukrainian Air Force has publicly stated its hopes for F-15s and F-16s.

Brown acknowledged that discussions within the U.S. military and its allies on the issue are ongoing.

"You want to build a long-term plan on how do you build their air force and the air force that they're going to need for the future," said Brown, a pilot himself, without confirming any decisions on the way forward.

Brown's comments came days after lawmakers in the House put forward a measure that, if it passes other hurdles, would provide $100 million to train Ukrainian pilots and technicians on American combat aircraft.

Brown declined to comment on the bill. He also declined to talk about timelines or which Western aircraft are best suited for Ukraine.

But he noted that the future training of Ukrainian pilots is a complex issue that must take into account the state of war and Kiev's ability to take pilots off the battlefield for lengthy briefings.

When asked how long it would take a Ukrainian pilot to switch to an American fighter jet, Brown noted that an American pilot could be trained on the new type of aircraft within two to four months. He said the transition from the Soviet system would be "a little harder."

Brown said Ukraine could look to NATO allies with experience in transitioning from Soviet-era aircraft to Western systems. "I feel pretty confident there are some of our NATO partners who have done that, can actually have lessons that they learned that can be helpful to the Ukrainians to help them figure out how to best make that transition," Brown said.