The state-owned English language IRAN daily has quoted ministry spokesman Mohammad Ali Hosseini denouncing the remarks as "inappropriate" and describing McCain's attitude as "regretful."
Last week, McCain was asked about an Associated Press report that the U.S. exported $158 million worth of cigarettes to Iran during the Bush administration in spite of restrictions on U.S. imports.
"Maybe that's a way of killing them," McCain said. He then said that he was joking.
Iran has officially announced that it supports neither U.S. presidential campaign but does hope the election will bring a change in U.S. foreign policy.