WASHINGTON: US Secretary of State John Kerry appeared to criticize Israel in candid remarks caught on an open microphone between television interviews Sunday.

Kerry was heard talking about Israeli soldiers killed in Gaza to a State Department official identified as Jonathan Finer just before appearing on the “Fox News Sunday” political talk show.

“I hope they don’t think that’s an invitation to go do more,” Kerry says. “That better be the warning to them.”

A frustrated Kerry then says: “It’s a hell of a pinpoint operation, it’s a hell of a pinpoint operation,” in apparent frustration over the civilian toll in the Israeli operation.

“We’ve got to get over there,” Kerry is heard saying on the Sunday recording. “I think, Jon, we ought to go tonight. I think it’s crazy to be sitting around. Let’s go.”

When confronted over the remarks by Fox host Chris Wallace, Kerry reiterated Israel’s right to self-defense. “I think it’s very, very difficult in these situations, obviously very difficult,” Kerry said. Kerry then urged Hamas to “step up and be reasonable and understand that you accept the cease-fire, you save lives.”

Kerry is making a renewed push for a cease-fire with another trip to the Middle East. Kerry left Washington early Monday for Cairo, where he will join diplomatic efforts to resume a truce that had been agreed to in November 2012. He will urge Hamas to accept a cease-fire agreement offered by Egypt.

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

Two Americans, Max Steinberg of California and Nissim Carmeli of Texas, who fought for the Israel Defense Forces were killed in fighting in the Gaza Strip. The State Department confirmed the names of the two US citizens Sunday night.

Over 70,000 Palestinians have fled their homes in the fighting and are seeking shelter in schools and other shelters the UN has set up.