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JERUSALEM -- Asserting it has broad international support for a fierce military offensive in the Gaza Strip, Israel is showing no signs of ending the operation, vowing to press on until there is a halt to rocket attacks from the seaside territory.
But a mounting Palestinian civilian death toll is beginning to draw international criticism and could quickly put the brakes on the campaign.
Israeli officials say they are pleased with the results of the four-day operation so far.
Military officials say the round-the-clock airstrikes have hit Hamas hard, taking out the militant group's command centers, rocket-launchers and storage sites, and knocking out much of its long-range rocket arsenal.
Addressing a nationally televised news conference Friday, Prime Minister Benjamin Netanyahu said the offensive was progressing well and brushed off a question about a possible cease-fire, suggesting the campaign will continue for some time. He also refused to rule out a ground offensive.
"I will end it when our goals are realized. And the overriding goal is to restore the peace and quiet," Netanyahu said.
In four days, Israel has pummeled more than 1,000 targets in Gaza -- twice the rate of the 2012 operation.
More than 100 Palestinians have been killed, including dozens of civilians, according to the Health Ministry in Gaza.
Adding to Israel's technological edge, the "Iron Dome," a U.S.-funded, Israel-developed rocket defense system, has intercepted more than 100 incoming rockets, preventing any Israeli fatalities so far. Palestinian militants have fired more than 600 rockets, most falling in open areas.
Asked about reaching a possible cease-fire, Netanyahu evaded the question. Instead, he said he has held phone conversations with key allies, including President Barack Obama and the leaders of Germany, Britain, France, Canada and Russia.
He described the talks as positive and said he had told his counterparts that no country would tolerate rocket attacks on its citizens.
"No international pressure will prevent us from acting with all power," he said.
Netanyahu rejected criticism of the death toll among civilians, saying that Israel does everything possible to protect them. He accused Hamas of putting civilians in harm's way by using residential areas for cover.
At least 35 of the dead, and perhaps many more, were civilians, including an 80-year-old man, an 80-year-old woman and 17 children under the age of 13, according to a tally by The Associated Press. Israel, for instance, is investigating an airstrike that killed eight members of a single family.
Should the civilian death toll continue to rise, Israel could see international support crumble and face calls for restraint, as has been the case during past offensives in Gaza, Lebanon and the West Bank.
Israel's ambassador to the U.S., Ron Dermer, told reporters that Israel has "strong diplomatic backing for what it's trying to do."
For now, international criticism of Israel appears to be muted. White House spokesman Josh Earnest reaffirmed "Israel's right to defend itself," although he also called for the sides to "restore calm" and to protect innocent civilians.
Britain, another close ally, this week also offered its "staunch support" for Israel's right to self-defense, while Canadian Prime Minister Stephen Harper "reiterated Canada's steadfast support for Israel," his office said.
But the support has not been wall-to-wall.
France, home to Europe's largest Jewish and Muslim populations, has sent mixed messages. Early this week, President Francois Hollande said Israel should "take all measures" to protect its population. But following some criticism, he later deplored "the numerous Palestinian victims" and said "the escalation must cease."
The European Union also has been measured, condemning the indiscriminate rocket fire from Gaza on Israeli population centers but also deploring the growing number of civilian casualties.
Civilians would be especially at risk if Israel begins the ground operation. The army has massed thousands of forces along the border.
Israel has come under some criticism. U.N. Secretary-General Ban Ki-moon expressed his concern over the civilian deaths. And the U.N. human rights chief said Friday the Israeli air campaign may violate international laws prohibiting the targeting of civilians.
"We have received deeply disturbing reports that many of the civilian casualties, including of children, occurred as a result of strikes on homes," said Navi Pillay, the U.N. high commissioner for human rights. She called for an immediate cease-fire.
For now, cease-fire efforts show few signs of taking hold. After White House offers to help facilitate a truce, U.S. Secretary of State John Kerry is considering a trip to the region next week, a U.S. official said Friday.
The official, speaking on condition of anonymity because he was not authorized to talk to the media, said the U.S. wants a cease-fire but doesn't want a result that rewards Hamas or weakens Israel. He said Hamas must stop firing the rockets.
Efforts to end the crisis have been complicated by a more muted role by Egypt, which historically has served as a mediator between Israel and Hamas.
In the 2012 fighting between Israel and Hamas, Egypt's then-President Mohammed Morsi brokered a cease-fire, leveraging the influence his Muslim Brotherhood held with its ally Hamas.
Morsi was ousted in 2013 by Egypt's military. His successor, President Abdel-Fattah el-Sissi -- the former head of the military -- has taken a more behind-the-scenes role in the current crisis. His government says he has been in contact with both the Israelis and the Palestinians to find a solution. But if Egypt has put forward any proposals for a resolution, none have been made public.
With little desire to help Hamas, the Egyptian government has, however, sought to show it is supporting the Palestinians by ordering food and medical supplies sent to Gaza and allowing some wounded into Egypt.
Egypt's Foreign Ministry accused Israel of "excessive and unjustified use of military force" and continuing "policies of repression and mass punishment." But it only urged Israel to show restraint and "consider the humanitarian aspect" -- while calling on both sides to stop violence and abide by the 2012 truce.
Hamas officials said the group is ready for a cease-fire, but only if it gets something in return, such as a restoration of the 2012 truce and the release of prisoners arrested by Israel in a recent crackdown. They said the group has been in touch with Egypt, Qatar and Turkey as possible mediators.
"We have contacts with various Arab and international parties but Israel is showing intransigence," said Ghazi Hamad, a top Hamas official in Gaza.
Yousur Alhlou in Jerusalem, Julie Pace and Bradley Klapper in Washington, Lee Keath in Cairo, John-Thor Dahlburg in Brussels, Danica Kirka in London, Charmaine Noronha in Toronto and Elaine Ganley in Paris contributed to this report.