Story highlights Former President Carter said exiting the Iran nuclear deal sends mixed signal to North Korea

President and Mrs. Carter were honored with the Bill Foege Global Health Award on Wednesday

(CNN) President Donald Trump's decision to pull the United States out of the Iran nuclear deal is a "serious mistake," said former President Jimmy Carter in an interview with CNN Chief Medical Correspondent Dr. Sanjay Gupta on Wednesday.

Trump announced Tuesday that he is walking away from the deal, which curbed Tehran's nuclear program in exchange for sanctions relief . The decision, which Carter also referred to as "ill-advised," pits Trump against US allies, and leaves the future of the agreement under a cloud of uncertainty.

In announcing his decision, Trump said he would initiate new sanctions on the regime , crippling the agreement negotiated by his predecessor, and he said any country that helps Iran obtain nuclear weapons would also be "strongly sanctioned."

This "may be the worst mistake Trump has made so far," Carter said.

"When a president signs an agreement, it should be binding on all his successors, unless the situation changes dramatically and it hasn't changed," he said. "Unfortunately, I think it signals a message to North Korea that if the United States signs an agreement, it may or may not be honored."