White House Press Secretary Robert Gibbs admitted Sunday he hasn't yet mastered the art of tweeting.

“It takes an amazing amount of discipline to write out all of what you want to say in 140 characters or less,” he told CNN’s “Reliable Sources” in an interview that aired this morning. “If you ever watch me do it, it takes me a few minutes to sort of edit even myself down.”

"I just think it's a fascinating, fast-moving medium," he added.

Gibbs joined Twitter in February, long after Deputy Press Secretary Bill Burton took to the medium.