US President George Bush has said he will urge Israel to avoid civilian casualties in its attacks on Lebanon.
George Bush has not publicly criticised Israel's bombardment
But he did not say he would demand an end to Israel's bombardment, according to the office of Lebanese Prime Minister Fuad Siniora.
Israel has hit strategic sites in Lebanon, and Hezbollah strongholds.
President Jacques Chirac of France called Israel's acts "disproportionate" while Russian President Vladimir Putin called for an end to fighting.
Mr Putin, who is hosting a meeting of the G8 group of top industrialised countries in St Petersburg, said "all sides implicated in this conflict should immediately stop military action," Interfax news agency reported.
He was expected to discuss the conflict with Mr Bush and other leaders at the conference.
Mr Bush has not publicly criticised Israel's actions, but told Mr Siniora in a telephone call that he would urge Israel to limit the damage.
Mr Chirac criticised the Lebanese-based militant group Hezbollah, which has captured two Israeli soldiers, and the Palestinian Hamas, which has another, saying they were engaged in a process of "provocation-repression".
"These people are totally irresponsible," he said.
But he said Israel's response was "completely disproportionate", adding: "One can ask oneself whether there isn't a sort of desire to destroy Lebanon."
The United Nations' top humanitarian official said Israel's actions, including its blockade of Lebanese borders and trading points, could have grave consequences for civilians.
Jan Egeland was also critical of the militant groups, but said: "You are supposed to do something to the armed group. You are not supposed to hurt the children of people who have nothing to do with this."
He said ordinary people "cannot receive goods, cannot travel, cannot get to health facilities, cannot get their daily needs met" because of the Israeli operation.
Iranian President Mahmoud Ahmadinejad accused Israel of "continuous oppression, aggression and threat".
"It uses any excuse to show its teeth and fangs and attack. It attacks Lebanon one day and Gaza another day," he said.
Iran's top conservative cleric, Ayatollah Mohammad Emami Kashani, in a Friday sermon backed Hezbollah, which it said was acting "based on their legal, religious and legitimate rights".
He said Muslims around the world should support the militants.