AP National Security Writer
CAIRO (AP) -- With high hopes but low expectations, the U.S. stepped up calls Monday for an international push to end fighting in the Gaza Strip as President Barack Obama sent his top envoy to the Mideast to help broker a new cease-fire between Israel and Hamas militants -- the third since 2009.
Voicing fresh concern about civilian casualties, Obama reaffirmed his belief that Israel has the right to defend itself against a barrage of more than 1,500 rockets being launched by Hamas.
Yet he said Israel's military assault of Gaza had already done "significant damage" to Hamas' network of tunnels, safe havens and other infrastructure, and said he doesn't want to see more civilians getting killed.
"We have serious concerns about the rising number of Palestinian civilian deaths and the loss of Israeli lives," Obama said in Washington. "And that is why it now has to be our focus and the focus of the international community to bring about a cease-fire that ends the fighting and can stop the deaths of innocent civilians, both in Gaza and in Israel."
As Obama spoke, U.S. Secretary of State John Kerry flew to Cairo to join diplomatic efforts to resume a truce that last had been agreed to in November 2012. He will urge the militant Palestinian group to accept a cease-fire agreement offered by Egypt that would halt two weeks of fighting that has descended into war and killed at least 500 Palestinians and more than two-dozen Israelis.
Kerry headed almost immediately into a meeting with U.N. Secretary General Ban Ki-Moon, where he announced the U.S. will send $47 million in humanitarian aid for tens of thousands of Palestinians who have fled their homes in Gaza to escape the violence. Kerry's top aides warned, however, that achieving an immediate and lasting cease-fire would be difficult and he hoped to make any progress over the next several days to secure even a temporary pause in the bloodshed.
Ban, speaking to reporters before the meeting with Kerry, said he was disappointed that nine months of U.S.-led talks between Israel and the Palestinians hadn't yielded better results. Those negotiations broke off last April after it was clear that neither side would make major concessions needed to clinch a peace plan.
"Violence must stop and must stop now," Ban told reporters. He added, "We can't claim victory simply by returning matters to where they stood before, which led to terrible bloodshed."
It's not clear exactly what Israel and Hamas would each demand in return for agreeing to a truce now, but senior State Department officials said the issue of opening border crossings -- potentially into Israel and Egypt -- was under discussion.
"We will work to see if there is some way to not only arrive at a cease-fire of some kind but to get to a discussion about the underlying issues," Kerry said at the start of his meeting with Ban. "Nothing will be resolved by any cease-fire, temporary or long, without really getting to those issues at some point and that's what we need to do."
Kerry is expected to meet with top officials, including President Abdel Fattah al-Sisi, Foreign Minister Sameh Shukri and Arab League President Nabil Elaraby over the next few days. But there were no immediate plans for face-to-face meetings with officials from Qatar, Turkey, Israel and Ramallah, and the State Department aides said it remained uncertain what could be accomplished in the talks.
A truce between Israel and Hamas has been beset by violence three times since 2009, and was last brokered in November 2012 by Kerry's predecessor, Hillary Rodham Clinton.
On Monday, the senior State Department officials said they believed it would be more difficult now to reach a new agreement.
Having already deployed an estimated 1,000 ground troops, Israel's military has pushed farther into Gaza than it had in 2012 and the conflict is farther along now than it was then. At the same time, the State officials noted, Hamas believes it was not given what it was promised in 2012 to lay down its arms, making it more skeptical of a cease-fire now. Finally, Hamas's relationship with Egypt, which is negotiating directly with the militant group, has deteriorated since President Mohammed Morsi was ousted in last year's coup. Egypt has since outlawed Morsi's party, the Muslim Brotherhood, which has ties to Hamas.
Sharp ideological divisions in the region have grown even deeper over the last two years. It remains unclear, for example, the extent to which nations like Egypt and Qatar are working together on a cease-fire proposal. Egypt has already offered one plan, which is backed by Israel and the U.S. But Hamas is looking to governments in Qatar and Turkey -- both of which are also linked to the Muslim Brotherhood -- to make sure its interests are represented.