Washington  - US presidential candidate John McCain joked with reporters that one way of killing Iranians was to send them cigarettes, news reports said Wednesday.

A journalist asked McCain for a reaction to reports that US exports to Iran increased tenfold during the current administration of President George W. Bush. The reporter mentioned that the biggest export was cigarettes.

McCain laughed and said, "That's a way of killing them," according to CNN footage on YouTube.

As others around him laughed uncomfortably and his wife Cindy poked him in the back, McCain quickly said: "I meant that as a joke ... as a person who hasn't had a cigarette in 28 years." And then he looked back at his wife again, who corrected him and said "29 years."

The conversation took place as the couple was getting ready to dine late Tuesday at a restaurant in Pittsburgh, according to a report in the Pittsburgh Tribune-Review.

Early in his campaign, he 'joked' about "bombing Iran," to the tune of the Beach Boys' popular song 'Barbara Ann.'

McCain, 71, is a decorated war hero with a Senate career of more than 20 years that has largely focused on foreign policy issues. (dpa)