A Ukrainian Sukhoi Su-27 fighter jet is seen during an event last month.
The status of a USA pilot remains unclear after a Ukrainian fighter crashed on Tuesday during joint exercises in western Ukraine.
The U.S. Air Force command based in Europe said the American pilot, who was not identified, was among the two pilots on board at the time.
Senyk said the two-seater jet was flying as part of large-scale air force exercises called Clear Sky 2018 involving the United States and other North Atlantic Treaty Organisation countries, which began on October 8.
Ukraine on October 8 began a series of large-scale air force exercises called Clear Sky 2018 with the United States and other North Atlantic Treaty Organisation countries.
A statement said it "can confirm a US service member was involved in this incident", but stopped short of confirming the American's death.
A Ukrainian Su-27UB fighter jet has crashed during a joint large-scale aviation exercise Clear Sky 2018.
U.S. Air Force pilots are now in Ukraine participating in a large-scale multi-national aviation exercise known as "Clear Sky" involving close to 1,000 personnel from North Atlantic Treaty Organisation countries.
"Training will focus on air sovereignty, air interdiction, air-to-ground integration, air mobility operations, aeromedical evacuation, cyber defense, and personnel recovery", the Air Force said at the time.
Other U.S. aircraft participating in the exercise include California ANG C-130s sent to Vinnytsia Air Base; Illinois ANG KC-135s from Powidz Air Base, Poland, and active duty KC-135s from from RAF Mildenhall, England; as well as MQ-9 Reapers based at Miroslawiec Air Base, Poland.