U.S. Secretary of State John Kerry is headed to Egypt today in an effort to broker a cease-fire between Israel and Hamas.
In a statement, State Department spokeswoman Jen Psaki said Kerry would meet with Egyptian and other senior officials.
"The United States and our international partners are deeply concerned about the risk of further escalation, and the loss of more innocent life," Psaki said. "We believe there should be a cease-fire as soon as possible one that restores the cease-fire reached in November of 2012."
According to a New York Times count, Sunday's fighting was the deadliest in the 14-day conflict. Ninety-five Palestinians and 15 Israelis were killed.
NPR's Soraya Sarhaddi Nelson reports that 13 of those Israelis were soldiers, two of whom were American citizens.
Soraya adds that the Israeli military on Sunday said it had foiled an attempt by Hamas militants to infiltrate into southern Israel. According to Israeli Army Radio, the militants entered Israel using two tunnels from northern Gaza.
Meanwhile, on the diplomatic front, the United Nations Security Council had an emergency meeting on Sunday night and emerged calling for an immediate cease-fire.
In Qatar, Secretary-General Ban Ki-moon echoed those calls, saying Israel must end its military incursion and Hamas must end its rocket fire.
Ban added: "While I was en route to Doha, dozens more civilians, including children, have been killed in Israeli military strikes in the Shejaiyah neighborhood in Gaza. I condemn this atrocious action. Israel must exercise maximum restraint and do far more to protect civilians."
Since the conflict started, 25 Israelis and more than 500 Palestinians have been killed.
Update at 1:42 p.m. ET. 7 IDF Soldiers Killed:
Israel Defense Forces says seven of its soldiers have been killed during this conflict in the past 24 hours.
According to Haaretz, that brings the total number of Israelis killed to 25. The paper puts the total number of Palestinians killed at 508 with 3,130 wounded.