WASHINGTON — U.S. Secretary of State John Kerry is making a renewed push for a cease-fire between Israel and Hamas with another trip to the Middle East after the civilian death toll in the conflict sharply escalated over the weekend.

Kerry left Washington early today for Cairo, where he will join diplomatic efforts to resume a truce that 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 nearly two weeks of fighting. More than 500 Palestinians and 20 Israelis have been killed in that time.

The Obama administration, including Kerry, is sharpening its criticism of Hamas for its rocket attacks on Israel and other provocative acts, like tunneling under the border. It is also toning down an earlier rebuke of Israel for attacks on the Gaza Strip that have killed civilians, including children.

In a statement Sunday evening, State Department spokeswoman Jen Psaki said the U.S. and international partners were “deeply concerned about the risk of further escalation, and the loss of more innocent life.”