Obama voices 'serious concern' to Netanyahu

President Obama voiced "serious concern" to Israeli Prime Minister Benjamin Netanyahu on Sunday over the growing number of casualties from its ground offensive in Gaza.

A White House readout of the call said the concerns related to increasing deaths among Palestinian civilians and also the loss of Israeli solders.

Sunday was the worst day of fighting so far, according to The New York Times, with 87 Palestinians and 13 Israeli soldiers pronounced dead. A total of 417 Palestinians have been killed in Gaza since July 9.

The White House is walking a fine line with regard to the conflict, emphasizing Israel's right to defend itself against Hamas but cautious about endorsing actions that could result in more civilian deaths.

Secretary of State John KerryJohn Forbes KerryBreitbart editor: Biden's son inked deal with Chinese government days after vice president’s trip State lawmakers pushing for carbon taxes aimed at the poor How America reached a 'What do you expect us to do' foreign policy MORE will travel to Cairo to work on a potential cease-fire based on a previous agreement from November, 2012, Obama told Netanyahu on Sunday.

Kerry will travel to Egypt on Monday to meet with Egyptian and other senior officials, the State Department said.

"The United States – and our international partners– are deeply concerned about the risk of further escalation, and the loss of more innocent life," department spokeswoman Jen Psaki said in a statement late Sunday. "We believe there should be a ceasefire as soon as possible – one that restores the cease-fire reached in November of 2012. Secretary Kerry is working to support Egypt’s initiative to pursue that outcome, and will travel to the region as part of those efforts. "

--This report was updated at 6:02 p.m.