ST. PETERSBURG, Russia – World leaders tore up a carefully prepared summit agenda Saturday and turned their attention to a growing crisis in the Middle East, hoping to reach common ground on ways to stop the fighting.

Russian President Vladimir Putin said he was grateful that President Bush came early for bilateral talks that Putin said would allow them to synchronize their watches on a host of world crises and provide a “boost to the G8 summit.”

Putin designed this year’s Group of Eight economic summit, the first to be held in Russia, to showcase his country’s re-emergence on the world stage after a devastating economic collapse in 1998. He had hoped to focus on energy security, the fight against infectious diseases and education.

But officials were quickly clearing discussion time to address a new explosion of violence in the Middle East. The G8 countries – the United States, Russia, Japan, Germany, Britain, France, Italy and Canada – were expected to issue a joint declaration on the Lebanon crisis but drafters of the document faced the need of dealing with sharp differences between the United States and the other countries over how to proceed.

Israel’s war planes began striking Lebanon after Hezbollah guerrillas captured two Israeli soldiers and killed eight others Wednesday in a cross-border raid into Israel. Since Wednesday, Hezbollah has fired hundreds of rockets at northern Israel.

Bush said that Israel has a right to defend itself while other summit leaders have condemned what they see as an overreaction on the part of Israel that has caused dozens of civilian deaths and risked a major escalation of bloodshed in the Middle East.

But Stephen Hadley, Bush’s national security adviser, said he believed the G8 leaders would be able to overcome differences to reach a joint position on stopping the violence.

“I think it is coming together. What we need is a strategy that can achieve the objective,” Hadley said. He said there was a need to “put maximum pressure on Hezbollah to stop the rocket attacks” on northern Israel.

The other G8 leaders flew into St. Petersburg for three days of discussion beginning with an opulent dinner at a former czarist palace on Saturday night. Bush and the other leaders were staying in guest houses on the grounds of the Konstantin Palace on the Bay of Finland, an area that was sealed off by heavy security.

Anti-globalization protesters vowed to march in St. Petersburg despite an official ban and warnings from a top Kremlin official against violating a ban on marches. City authorities have limited the activities of protesters to a stadium in a hard-to-reach part of St. Petersburg.

In a joint news conference with Putin, Bush said Saturday that “all parties want the violence to stop” in Lebanon. In his comments, he blamed the Islamic militant group Hezbollah for escalating the violence.

However, Putin and other G8 leaders have been more critical of Israel.

Putin said that while Israel’s concerns about the abductions and missile strikes were justified, “the use of force should be balanced.”

The sudden flare-up of violence was threatening to hijack this year’s summit, which already was facing the need to address nuclear threats being posed by Iran and North Korea.

Italian Premier Romano Prodi said the “spiral of violence” in the Middle East was an indication that the situation had “regressed 20 years.”

French President Jacques Chirac was even harsher in his comments about Israel, saying, “One could ask if today there is not sort of a will to destroy Lebanon, its equipment, its roads, its communications.”

As the summit was getting started, the United States and Russia announced that they had failed to reach agreement on a deal that would allow the United States to back Russia’s application to join the 149-nation World Trade Organization, the group that sets the ground rules for global trade.

Putin had hoped a deal at the time of the summit would highlight the rebound of Russia’s economy since the devastating collapse of the ruble, the country’s currency, during the global financial crisis of 1998.

Bush said trade negotiators would continue working for a deal but he said his administration needed to see firm commitments that would win support for the deal in Congress. The United States is pressing Russia to open its markets more to American products and halt the piracy of American movies, music and computer programs which U.S. companies claim are costing them billions of dollars in lost sales.