(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.

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