WASHINGTON, August 29. /TASS/. The US Department of Defense declined to comment on Ukraine’s first loss of a donated US-made F-16 fighter jet.

"For this query we refer you to the government of Ukraine," a Pentagon spokesman told TASS.

An unidentified US official told Reuters that the plane crash was not caused by Russian forces.

The Wall Street Journal reported, citing a US official, that Kiev for the first time lost one of the US-made fighter jets that had been donated shortly before. The official said the plane was not shot down and that the crash was likely caused by pilot error.