Cindy Hyde-Smith, a Republican senator from Mississippi, congratulated the US Air Force Reserve Command on Twitter with a picture of Russian Su-34 fighter-bomber/strike aircraft.
Congratulating the military personnel with the 73rd anniversary of their major command, she thanked "all the reservists who are constantly on the ready to serve our nation".
It was the picture in the background, however, that attracted the attention of many social media users, who wondered if they had somehow missed any changes that had been made.
After users reacted furiously to the senator's mistake, Hyde-Smith hastened to remove the post and change it with one containing the appropriate background picture.
However, some users called it a national pastime for Americans to pass off Russian weapons as their own.