WATCH: Ex-RNC chair reveals the hilarious ‘tell’ so you know when Trump is lying
Composite image of Michael Steele and Nicolle Wallace (screengrabs)

The former head of the Republican Party revealed one "tell" that Americans can employ to know when President Donald Trump is lying.

MSNBC's Nicolle Wallace interviewed Michael Steele on Friday's "Deadline: White House."

"Whenever the president said, 'I heard' -- shut it down, stop it, call it a lie and move on because the next sentence, word, phrase out of his mouth will be a lie," Steele explained.

"Stop it. Press, don’t write that story. It is a lie. Whenever he comes out with the 'I heard' or 'people say,' that’s a tell," he said.

"Or my friend Jimmy," Wallace interjected. "Jimmy's never real."

"Jimmy doesn't exist," Stelle replied. "Jimmy is in his head."

"Jimmy is running from this eyeball to that eyeball, do you understand that? This is where Jimmy plays, he's right here," Steele said, pointing between his eyes.