Mr. Paul told Fox News’s Chris Wallace that he opposes sanctions on Iran. Citing continuous reports over the last decade that Iran was close to making a nuclear weapon, Mr. Paul sounded skeptical that Tehran was about to do so.

In any event, he said, sanctions were not the way to dissuade Iran from becoming a nuclear state.

“Sanctions are acts of war . . . Don’t put sanctions on them,” Mr. Paul said. Offering friendship to Tehran could be more productive than punishing Iranians through sanctions, he said.

“For them to be a threat to us or anyone in the region is blown out of proportion,” he said.