(CNN)The Republican candidates for U.S. president who are attacking the nuclear deal with Iran could hardly find the country on a map, or know that Tehran is the capital, Iranian President Hassan Rouhani told CNN's Christiane Amanpour on Sunday.

"Sometimes when I would have time, some of it was broadcast live and I would watch it -- some of it was quite laughable. It was very strange, the things that they spoke of," he said through an interpreter.

"Some of them wouldn't even know where Tehran was in relation to Iran. Some of them didn't know where Iran was geographically, not distinguishing that one is the capital of the other."

"So what they spoke of was quite far away from the truth. So the people of Iran were looking at it as a form of entertainment, if you will, and found it laughable."

The U.S. Congress failed to block the implementation of a deal between Iran and six world powers that trades curbs on Iran's nuclear program for the elimination of many sanctions that have been placed on the country.

But Republican candidates for president have vowed to tear up the deal if elected.

"I will rip to shreds this catastrophic Iranian nuclear deal," Ted Cruz said in a recent CNN debate.

Were the U.S. to do that, Rouhani said, it would destroy the country's credibility abroad, and Iran would abide by its commitment to the deal.

"Can a government become a signatory to an international agreement and then the subsequent government tear it to shreds? This is something that only the likes of Saddam Hussein would do," he said.

"Saddam Hussein, previous to attacking Iran in 1980, did sign an agreement with Iran and then tore it to shreds himself and then attacked Iran."

"So any government that replaces the current government must keep itself committed to the commitments given by the previous administration; otherwise, that government, that entire country, will lose trust internationally and no longer have the type of needed trust to operate in the international arena."

"So finally, I think most of these are political slogans at best."

By CNN