The United States condemned rocket fire by Hamas militants into Israel and said it was concerned for civilians on both sides after Israeli strikes on Gaza killed 17 people Tuesday.

White House spokesman Josh Earnest also urged Israeli Prime Minister Benjamin Netanyahu to keep a diplomatic channel open with Palestinians to resolve the crisis sparked by the murders of three Israeli teenagers and a Palestinian youth.

"We strongly condemn the continuing rocket fire into Israel and the deliberate targeting of civilians by terrorist organizations in Gaza," Earnest said.

The spokesman also backed the Jewish state's right to respond to the attacks.

"No country can accept rocket fire aimed at civilians and we support Israel's right to defend itself against these vicious attacks," he said.

At the same time, Earnest said Washington was mindful of the plight of civilians caught in the crossfire between Israel and Hamas.

"This means both the residents of southern Israel who are forced to live under rocket fire in their homes and the civilians in Gaza who are subjected to the conflict because of Hamas' violence," he said.

Hamas claimed responsibility for the attacks, including rockets fired into Jerusalem and Tel Aviv.

The US State Department called on Palestinian president Mahmud Abbas to lean on leaders of Hamas, which joined a unity government last week with the Palestinian Authority.

"We certainly expect president Abbas to do everything in his power to prevent rocket attacks and to condemn violence, and he has made a range of those calls," State Department spokeswoman Jen Psaki said.

"But we're conveying the same message to him as well about the need to exercise restraint and de-escalate the situation on the ground."

As for the stalled Israeli-Palestinian peace talks, Psaki added that "it's difficult to see how the reconciliation process can move forward in the current atmosphere."

Emergency services in Gaza said that Israeli strikes killed 17 people and wounded more than 100 others, as the military began an aerial campaign against militants in the Strip.

Israeli army figures showed that militants fired 130 rockets at southern Israel without causing any casualties, while the Israeli air force struck 150 "terror targets" in Gaza.