"Israel's policy is consistent and has not changed. Israel demands the release of all 50 hostages in accordance with the principles established by the cabinet for ending the war. We are in the final decisive stage of Hamas and will not leave any hostage behind," an Israeli political source said.

Israel is studying Hamas' response to a Gaza ceasefire proposal, two officials said on Tuesday of a potential deal for a 60-day truce and the release of half the Israeli hostages still held in the battered enclave.

It was unclear whether Prime Minister Benjamin Netanyahu of Israel was on board with the terms, which came as Qatar and Egypt were intensifying mediation efforts.