Israel's Benjamin Netanyahu has called US President Barack Obama and the two discussed options for "de-escalating" the situation in Israel and Gaza.
Obama "reiterated US support for Israel's right to defend itself, and expressed regret over the loss of Israeli and Palestinian civilian lives," according to a statement on the call from the White House.
"The prime minister expressed his deep appreciation to the president and the American people for the United States' investment in the Iron Dome rocket and mortar defense system, which has effectively defeated hundreds of incoming rockets from Gaza," the statement said.
Israel was condemned on Thursday by much of the Arab world while securing Western backing and pressing its biggest air assault on Gaza for years.
IThe Israeli airforce launched three raids on targets in the Gaza Strip early on Tuesday.
Military commander of Hamas Ahmed Al-Jaabari was killed in an airstrike on the Gaza Strip on Wednesday. Islamist Hamas said Al-Jaabari, who ran the organisation's armed wing, Izz el-Deen Al-Qassam, died along with a passenger after their car was targeted by an Israeli missile.
Hamas has governed Gaza since 2007 and does not recognise Israel's right to exist. It has been emboldened by the rise to power in neighbouring Egypt of its spiritual mentors in the Muslim Brotherhood whom it views as a "safety net".
An emergency UN meeting concluded Wednesday without a decision and clear signals of concern over the first escalation of Middle East violence since the 2011 Arab Spring altered the political map of the historically volatile region.
British Prime Minister David Cameron told Netanyahu he was "extremely concerned" by violence in Gaza and urged him to do all he could to avoid civilian casualties.
French President Francois Hollande meanwhile held talks with Morsi on the phone, expressing France's "deep concern" and calling for "restraint", the president's office said. – Reuters, AFP, AP