"Today, around 17.00 local time [14:00 GMT], a Su-27 plane crashed near the village of Ulaniv [between the towns of Berdychiv and Khmil'nyk] during a combat training flight. Search and rescue activities are being carried out," the press service said in its Facebook blog.
In another statement, published on Facebook, the Ukrainian General Staff specified that the crew of the crashed fighter jet comprised a Ukrainian air force pilot and a US Air National Guard pilot.
The message, however, was deleted later.
At the same time, the US Air Force said in a press release that one American service member was involved in the crash.
"We have seen reports claiming a US casualty and can confirm a US service member was involved in this incident," the release said. "It is currently under investigation and we will continue to provide more information as it becomes available."
Earlier, it was reported that the Ukrainian Su-27 and the US F-15 fighter jets conducted a training mission within Clear Sky 2018 military drills.
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