ST. PETERSBURG, Russia — It wasn't meant to be overheard. Private luncheon conversations among world leaders, picked up by a microphone, provided a rare window into both banter and substance -- including U.S. President George W. Bush cursing Hezbollah's attacks against Israel.

Bush expressed his frustration with the United Nations and his disgust with the militant Islamic group and its backers in Syria as he talked to British Prime Minister Tony Blair during the closing lunch at the Group of Eight summit.

"See the irony is that what they need to do is get Syria to get Hezbollah to stop doing this s--- and it's over,'' Bush told Blair as he chewed on a buttered roll.

He told Blair he felt like telling UN Secretary General Kofi Annan, who visited the gathered leaders, to get on the phone with Syrian President Bashar Assad to "make something happen.'' He also suggested U.S. Secretary of State Condoleezza Rice might visit the region soon.

The unscripted comments came during a photo opportunity at the lunch. The leaders clearly did not realize that a live microphone was picking up their discussion.

Asked about the microphone mishap during his final briefing of the summit, Blair quipped that it was "all about transparent government.'' He smiled and tapped the microphone in front of him.

Bush "sort of rolled his eyes and laughed'' when told the comments had been audible and a copy had been made, said Press Secretary Tony Snow.

"Actually his reaction first was, `What did it say?' So we showed him the transcript, then he rolled his eyes and laughed,'' Snow said.

Bush also spoke to other leaders, and his unscripted comments ranged from the serious topic of escalating violence in the Mideast to light banter about his preference for Diet Coke and a gift he received from another leader.

Blair, whose remarks were not as clearly heard, appeared to be pressing Bush about the importance of getting international peacekeepers into the region.

Bush expressed amazement that it will take some leaders as many as eight hours to fly home, about the same time it will take Air Force One with Bush aboard to return to Washington.

"You eight hours? Me, too. Russia's a big country and you're a big country,'' Bush said, at one point telling a waiter he wanted Diet Coke. "Takes him eight hours to fly home. Russia's big and so is China. Yeah Blair, what're you doing? Are you leaving?''

Bush thanked Blair for the gift of a sweater and joked that he knew Blair had picked it out personally. "Absolutely,'' Blair responded, with a laugh.

A stickler for keeping to his schedule, Bush could also be heard telling Russian President Vladimir Putin, "We've got to keep this thing moving. I have to leave at 2:15. They want me out of town so to free up your security forces.''

Bush also remarked that some speakers at the meeting talk too long.

It was the second time in less than a month that remarks at a G8 event in Russia ended up being heard over an audio system officials thought was off.

Last month, an inadvertent audio feed from a closed-door lunch in Moscow between Rice and Russian Foreign Minister Sergey Lavrov exposed their sometimes testy discussion about the security situation in Iraq.