A Russian presidential envoy and an EU ministerial mission headed to the Middle East to try to agree a ceasefire while Israel battled Hamas fighters in the fields and roads of Gaza and the Palestinian death toll passed 500.
And in Washington, US Secretary of State Condoleezza Rice announced she was calling off a trip to China scheduled for later this week to deal with the crisis.
French President Nicolas Sarkozy, who starts a four-nation tour of the Middle East on Monday, said Hamas bore "a heavy responsibility" for the suffering of Palestinians in Gaza.
In an interview to be published Monday Sarkozy told three Lebanese newspapers that France condemned the Israeli ground offensive.
Sarkozy will be in Egypt, the West Bank and Israel on Monday and in Syria and Lebanon on Tuesday.
Egyptian President Hosni Mubarak has condemned "in the strongest terms" Israel's ground invasion of Gaza which his office called a "terrifying aggression."
Egypt on Sunday summoned the ambassadors of the UN Security Council's five permanent members to protest at its delay in passing a resolution for an end to Israel's onslaught, its foreign ministry said.
Late Saturday, the Security Council failed to agree on a statement calling for a ceasefire after the United States strongly backing Israel.
Jordan's King Abdullah II also insisted the UN Security Council act. "The king demanded the UN Security Council immediately issue a decision to stop the aggression, open the border crossings and end the humanitarian crisis in Gaza," a palace statement said.
British Prime Minister Gordon Brown said Israel's ground offensive marked a "very dangerous moment" in the conflict, and called for increased efforts to rapidly secure a halt in the fighting.