WASHINGTON, August 30. /TASS/. The US Department of Defense cannot confirm that the F-16 fighter jet previously handed over to Ukraine was downed by a Ukrainian Patriot air defense system in a friendly fire incident, Pentagon deputy press secretary Sabrina Singh told reporters at a regular briefing.

"I just can't confirm it. I don't have that level of fidelity right now. So in terms of if this pilot was killed and it was brought down by friendly fire - that I just can't speak to, that'd really be something for the Ukrainians to speak to," she said. "The United States has not been asked to participate in any type of investigation to look into this incident."

Earlier in the day, Ukrainian lawmaker Maryana Bezuglaya said the aircraft was mistakenly downed by a Patriot missile in a friendly fire incident.

Prior to that, an unidentified US official told the Wall Street Journal that Ukraine had lost a donated F-16 fighter jet in the first such case. According to the official, the jet was not shot down, and the crash was likely due to pilot error. Later, the Ukrainian Air Force confirmed the death of a Ukrainian F-16 pilot, Alexey Mes. The man was trained to fly F-16, according to CNN. The General Staff of the Ukrainian Armed Forces said the pilot was killed in an aerial fight, when his plane crashed on August 26.