British Prime Minister Gordon Brown echoed grave European concerns when he said the ground offensive was a “very dangerous moment” in the conflict, and he called for increased efforts to rapidly secure a cease-fire.

The offensive was condemned across the Middle East, with Egypt saying the U.N. Security Council's silence on Israel's eight-day campaign of air strikes had effectively given Israel “a green light” for the ground assault.

Asian nations expressed alarm, too, with Pakistan and China calling for an immediate end to the assault and Muslims in Indonesia urging war against the Jewish state.

But in New York, the Security Council failed to agree on a statement calling for a cease-fire after the United States argued that a return to the situation that existed before Israel's ground invasion was unacceptable. U.S. deputy ambassador Alejandro Wolff said after the four-hour sitting that Washington believed it was important that the region “not return to the status quo” that had allowed Hamas militants to fire rockets into Israel.

“The efforts we are making internationally are designed to establish a sustainable, durable cease-fire that's respected by all,” Wolff said. “And that means no more rocket attacks. It means no more smuggling of arms.”

As thousands of Israeli soldiers and scores of tanks pushed into Gaza Sunday, the British prime minister said assurances needed to be given to both the Israelis and Hamas to secure a cease-fire.

“I think everybody around the world is expressing grave concerns. What we've got to do almost immediately is to work harder than we've done for an immediate cease-fire,” Brown said on BBC television.

“I can see the Gaza issues for the Palestinians — that they need humanitarian aid — but the Israelis must have some assurance that there are no rocket attacks coming into Israel,” he said.

“So first we need an immediate cease-fire, and that includes a stopping of the rockets into Israel.”

Russia dispatched President Dmitry Medvedev's special envoy for the Middle East, Alexander Saltanov, to the region, hoping it could help bring about a cease-fire.

“The new dangerous escalation in the armed conflict after the start of the Israeli land operation in Gaza is a matter of extreme concern,” the Russian foreign ministry said in a statement. “It is essential, without delay, to put an end to the suffering of the civilian population on both sides, to stop the bloodshed and secure a mutual cease-fire.”

EU foreign policy chief Javier Solana said European nations stand ready to contribute international monitors to help keep the peace.

“The cease-fire has to be a cease-fire complied (with) by everybody and be clearly maintained,” Solana told the BBC.

European reaction to the ground offensive revealed a sharp difference in tone from the official U.S. line.

French Foreign Minister Bernard Kouchner said the decision to send troops into Gaza was a “dangerous military escalation”.

The European Union's new Czech presidency said Israel's ground operation was more “defensive than offensive”, although it said Israel did not have the right to take military actions “which largely affect civilians”.

Egyptian Foreign Minister Ahmed Abul Gheit said Israel's incursion into the impoverished territory was in “brazen defiance” of international calls to end the offensive — and he blamed the Security Council for failing to act.

“The Security Council's silence and its failure to take a decision to stop Israel's aggression since it began was interpreted by Israel as a green light,” he said.

In Asia, Pakistani Foreign Minister Shah Mehmood Qureshi said the Israeli offensive was “unjustified” and called for an immediate halt to the fighting.

Japanese Prime Minister Taro Aso warned that Israel's ground offensive would only aggravate difficulties for all concerned.

“I'm very worried that the dispatch of ground troops will make the situation much worse,” he said.

There was outrage in Africa as well.

Senegalese Pesident Abdoulaye Wade, who also holds the presidency of the Organisation of the Islamic Conference, called the Israeli ground offensive a “flagrant violation of the most elementary principles of international law.”