Matthew Morrison was mortified when he first met President Barack Obama, because the Glee star was dressed as a Nazi stormtrooper at the event.

The actor/musician was invited to perform at the annual Kennedy Center Honors in Washington, DC, in December to pay tribute to Mel Brooks, and he sang a version of the director's well-known song, Springtime for Hitler.

Morrison dressed in full Nazi uniform - complete with Swastika - for the performance, and he was still wearing the controversial costume later in the evening when he met the U.S. President.

He tells British TV show Loose Women, "We were honoring Mel Brooks and I sang Springtime for Hitler in a full Nazi stormtrooper outfit. It was actually the first time I met Obama, and I was wearing... I had a Swastika on and stuff. I was, like, 'This isn't how I envisaged meeting you, but hello Mr. President!"