In the wake of the U.S. downing a Syrian jet this weekend, the Russian defense ministry has announced it will no longer use the hotline it shares with the U.S. military.

FOX's Lucas Tomlinson has the details from the Pentagon:

After repeated warnings, a U.S. jet shot down a Syrian warplane Sunday after it fired on U.S.-backed rebels outside the ISIS stronghold of Raqqa.

It was the first time in 18 years an American military jet shot down another warplane in air-to-air combat. The last occasion was over Kosovo in 1999.

Today, Russian officials warned that U.S. and coalition warplanes operating west of the Euphrates River, operating over Syrian government controlled areas would be tracked as potential targets.

The Russians have made such threats before only to continue using the hotline.

At the Pentagon, Lucas Tomlinson, FOX News.

Follow Lucas Tomlinson on Twitter: @LucasFOXNews