The White House spokesman may have committed one of the biggest slips of the tongue in the recent history of the White House press room.

As questions flew during the daily briefing, White House spokesman Josh Earnest fielded a question from a Fox News reporter asking if he could deny that any member of the senior leadership at the White House lied to the American people about the Iran nuclear deal.

"No," Earnest replied before taking a long pause.

The reporter later offered Earnest a chance to clarify if he had "misspoke," and Earnest said that there was no proof that anyone within the administration lied about the Iran deal.

Story by senior correspondent Jason Wert.