Jimmy Carter: Trump's Exit From Iran Nuclear Deal 'Serious Mistake'

Former President Jimmy Carter called President Donald Trump pulling the U.S. out of the Iran nuclear deal was a "serious mistake."

Trump announced Tuesday that the U.S. would exit the Iran deal, which limited Iran's nuclear program in exchange for relief from sanctions.

That decision "may be the worst mistake Trump has made so far," Carter told CNN.

"When a president signs an agreement, it should be binding on all his successors, unless the situation changes dramatically, and it hasn't changed," Carter said in the CNN interview Wednesday.

Carter, who was president from 1976 to 1980, said that exiting the deal shows North Korea that the U.S. might not honor its commitments.

"I think it signals a message to North Korea that if the United States signs an agreement, it may or may not be honored," Carter said.

White House press secretary Sarah Huckabee Sanders pushed back against criticism of the exit from the deal from former President Barack Obama, as well as former secretaries of state Hillary Clinton and John Kerry.

"Based on each of those individuals' lack of success in this entire process on foreign affairs, they would probably be the last three people that we would look to for advice or counsel on whether or not we made the right decision," Sanders said to reporters Wednesday.

• Report: Kerry's Attempt to Save Iran Deal Played Part in Trump's Decision
• Tim Kaine: 'Blowing Up' Iran Nuclear Deal Not the Solution