"There is a burden, as I said before and as the president has said, on Israel to take the necessary steps to distinguish between Hamas, who does not represent the Palestinian people, and innocent Palestinian civilians," US National Security Advisor Jake Sullivan said on CNN talk show "State of the Union."

Sullivan added that US President Joe Biden will call Israeli Prime Minister Benjamin Netanyahu later Sunday to reiterate the US position that civilians must be protected.

Netanyahu announced Sunday a "second stage" of the war, adding that Israel is determined to bring back all the captives, while Palestinian fighters have continued firing rockets into Israel, with the constant sirens in southern Israel.

On Sunday, USS Dwight D. Eisenhower aircraft carrier and its strike group have moved through the Strait of Gibraltar, putting two American carriers in the Mediterranean Sea, a rare sight in recent years.

The USS Gerald R. Ford Carrier Strike Group is already in the eastern Mediterranean, part of a buildup of forces as the US supports Israel in its war on Gaza.