Two Ukrainian pilots in US for fighter jet training but still no decision on F-16s being sent to Ukraine
Two Ukrainian pilots are currently undergoing a training assessment in the US to fly American fighter jets, including F-16s.
The F-16 planes are believed to be the aircraft Ukraine wants the most to fight back against Russia's invasion in the skies.
Ukraine's president, Volodymyr Zelenskyy, has told Western nations the country needs jets to effectively fight the next stage of the war.
And at a military base in Tucson, Arizona, the US appears to be trying to provide some of the help the Ukrainians want.
The two pilots are being assessed and having their skills evaluated by simulators, according to two congressional officials and a senior US official.
A US defence official has called the training a "familiarisation event".
The programme sets out to improve the pilots' skills and evaluate how long a proper training schedule could take.
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'We haven't made the decision'
Officials have made clear that the Ukrainians will not be flying an actual aircraft - but instead using a simulator that can mimic flying various types of aircraft.
The pilots' presence in the country does not mean there are any updates on the US's decision to provide the fighter jets to Ukraine, officials also stressed.
"Since we haven't made the decision to provide F-16s and neither have our allies and partners, it doesn't make sense to start to train them on a system they may never get," said undersecretary for defence, Colin Kahl.
Mr Kahl predicted that the country would need between 50 and 80 F-16s to replenish Ukraine's current air force, at a cost of £9.1bn ($11bn), depending on the model and the number of aircraft delivered.
If a proper training programme does go ahead, it is estimated to take around 18 months, the same amount of time it would take for the US to send refurbished, older models of the jets to Ukraine.
New F-16s, built from scratch, would take as long as three to six years.
There are also no immediate plans to increase the number of pilots beyond the two in Tucson, but an official told NBC that they are "not closing the door on future opportunities".
Ukraine has told the US and other allies that they have fewer than 20 pilots ready to travel in order to undergo fighter jet training.
Last month, during an interview with ABC, President Joe Biden resisted repeated requests from Ukrainian President Zelenskyy to send as many as 128 aircraft, particularly F-16s, arguing that the country does not need them at this time.
Some officials have called for extra aid to be sent, in order to tackle Iranian-made drone attacks in Ukraine. At the end of last year, such attacks contributed to 4.5 million Ukrainians losing power.
But critics have warned that even with US fighter jets, the Ukrainian air force would be no match for Russia's, which is currently thought to have around 500 aircraft.