Mitt Romney on Friday congratulated Israel’s Prime Minister Benjamin Netanyahu on his speech to the UN General Assembly on Thursday, but joked that he thought about good-naturedly critiquing Netanyahu’s cartoon nuclear bomb graphic.

“I complimented him on his address,” the Republican presidential nominee told reporters. “I suggested that his graphic was not up to the usual Boston Consulting Group standards.” (Both men previously worked for the management consulting firm.) Romney paused, then added, “No, I didn’t actually do that.” He just thought about doing it, he said.

Netanyahu used the graphic to underline his demand for a “red line” that, if crossed, would prompt military intervention against Iran’s nuclear program — a red line, the prime minister said, that must ensure Iran does not amass enough 20%-enriched uranium for a bomb.

According to AP, Romney told Netanyahu in their phone conversation he doesn’t believe military action will be necessary to prevent Iran from obtaining nuclear weapons.

Romney later told reporters traveling with him that it’s unclear whether there is any difference between his and Netanyahu’s so-called “red lines” on when launching military action against Iran would be appropriate.

Romney says he can’t completely take the military option off the table because Iran needs to take the threat seriously. But he says he does not believe force will ultimately be needed.

Netanyahu argues that an attack on Iran’s nuclear facilities may be the only answer.

President Barack Obama also spoke to Netanyahu on Friday.