US president Barack Obama blamed Hamas for the swift collapse of the latest Gaza ceasefire, accusing the Palestinian group of launching a "barbaric" attack. President Obama said on Friday it would be "very hard" to get another truce in the Gaza Strip unless Hamas showed it was serious about laying down its arms and could be trusted to keep its word.

"If they are serious about trying to trying to resolve this situation, that soldier needs to be unconditionally released, as soon as possible," Obama told a surprise press conference.

"I think it's going to be very hard to put a ceasefire back together again if Israelis and the international community can't feel confident that Hamas can follow through on a ceasefire commitment."

But Obama also insisted that the deaths of "innocent civilians in Gaza caught in the crossfire have to weigh on our conscience and we have to do more to protect them." A three-day humanitarian ceasefire in Gaza collapsed only hours after it began amid a deadly new wave of violence.

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