An American-made F-16 fighter jet was lost in a crash on Monday, several weeks after the first of the fighters arrived in Ukraine, The Wall Street Journal wrote on Thursday, citing information from an unnamed American official.

"Initial reports indicate that the plane was not shot down by enemy fire, although the incident occurred during a massive Russian rocket attack across the country on Monday, the official said. Most likely, the crash was the result of pilot error," the report says.

The publication notes that, according to Ukrainian President Volodymyr Zelenskyy, Ukraine on Monday used the F-16 in combat for the first time to shoot down Russian missiles during strikes.

"The Ukrainian Air Force has not confirmed the crash or the status of the pilot. The Pentagon forwarded questions to the Ukrainian Air Force for comment," The Wall Street Journal said, noting that this piece of news was a serious blow to Kyiv, which had been asking for planes for months before President Biden finally gave the green light to European countries to transfer them."

On August 4, Ukrainian President Volodymyr Zelenskyy announced that the first of the 80 promised F-16s had arrived in Ukraine.

Another U.S. official told the ezine that a total of six planes had arrived in Ukraine, and Ukraine has six pilots trained to operate them.