The reason for lack of response from the pilots remains unclear to authorities.
US President Joe Biden told G7 leaders on Friday that Washington supports joint allied training programs for Ukrainian pilots on F-16s, senior US officials said.
Training on the US-made jets will take place in Europe and will require months to complete.
The US aircraft involved in the incident included F-16 and F-22 fighter jets, KC-135 stratotankers and E-3 AWACS, according to the statement.
According to the prior contract, Israel is due to receive another 14 in coming years, with about six more aircraft arriving each year.
Hundreds of people have been killed and thousands wounded since a long-simmering power struggle between the Sudanese army and the paramilitary Rapid Support Forces (RSF) erupted into conflict.
Take a look at just a few of the highlights from this year's Independence Day celebrations across the country.
Ankara is still running into trouble in Washington with defense procurement, as its airstrikes in Iraq and Syria are not making it new friends in the West.
The pilots said they made their decision following Prime Minister Benjamin Netanyahu's Thursday evening speech and will reconsider their decision in two weeks' time.
Moscow has accused the West of directly participating in the conflict through supplying weapons to Ukraine, and has warned before that NATO weapons were legitimate targets for its forces.
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