The United States called Thursday on Egypt, Turkey and European powers to press Hamas to end bloodshed in Gaza, putting the onus on the Islamist movement to end rocket attacks on Israel, AFP reports.
The White House said it was in close contact with Israel about its military campaign into the Hamas-controlled territory, in a conflict that officials said has killed 16 Palestinians and three Israelis.
"We've also urged those who have a degree of influence with Hamas such as Turkey an Egypt and some of our European partners to use that influence to urge Hamas to de-escalate," deputy national security adviser Ben Rhodes said.
"Our concern is, obviously, that Israel must be secure from these types of attacks and that, also, as this situation continues to unfold, it's only going to pose a greater threat to civilians and risk continued conflict in the region," Rhodes told reporters on a conference call.
The United States, Israel's closest ally, has backed Prime Minister Benjamin Netanyahu's calls for Hamas to put an end to rocket attacks into Israel in response to the military campaign.
"We strongly condemn the barrage of rocket fire from Gaza into Israel, and we regret the death and injury of innocent Israeli and Palestinian civilians caused by the ensuing violence," White House spokesman Jay Carney said.
"There's no justification for the violence that Hamas and other terrorist organizations are employing against the people of Israel," he added, saying it "does nothing to help the Palestinians."
He called on Hamas leaders to stop "these cowardly acts immediately to allow the situation to de-escalate."
State Department spokesman Mark Toner said separately of Hamas: "This is a situation that they've created by firing rockets on innocent Israeli civilians.
"You know, we obviously mourn civilian deaths on both sides. But the onus is on Hamas to stop its rocket attacks," Toner told reporters.
Obama spoke Wednesday by telephone to Netanyahu and urged him to "make every effort to avoid civilian casualties," while stressing Israel's right to defend itself from Hamas' attacks, the White House said.
Obama also spoke with Egyptian President Mohamed Morsi on Wednesday in recognition of Egypt's "central role in preserving regional security," the White House said.
US Secretary of State Hillary Clinton has spoken as well with her Egyptian counterpart Mohammed Amr, Toner said.
Egyptian Prime Minister Hisham Qandil is to visit Gaza on Friday to express his country's solidarity with the Hamas-ruled strip, Morsi's spokesman said.
Hamas spokesman Taher al-Nunu announced the visit and said "we welcome this visit and appreciate this courageous stand."
Toner said the US was hoping the Egyptian prime minister would deliver a message to halt the rocket fire into Israel.
Egypt in 1979 became the first Arab country to sign a peace treaty with Israel, and Toner said Thursday that the US believed the new leadership remained committed to that accord.
But Morsi, an Islamist elected in June after ex-president Hosni Mubarak's overthrow in 2011, has promised to take a harder line than his predecessor, who was accused of doing little to stop Israel's Gaza assault beginning in 2008.
The president's Muslim Brotherhood movement, which is closely aligned with the Hamas rulers of neighboring Gaza, has called for an economic boycott of Israel.
Turkey and some European nations maintain greater contact with Hamas than does the United States, which considers it a terrorist group.