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BEIRUT, Jan 17 (Reuters) - Hamas will fight on in Gaza against an Israeli offensive unless its demands are met, the Islamist group said on Saturday, indicating it would ignore a unilateral ceasefire if declared by the Jewish state.

Speaking in Beirut, Hamas' representative in Lebanon, Osama Hamdan, told a forum, "Today the movement's delegation arrives in Cairo. And clearly, we have nothing new to offer... Either we hear what we have demanded or the result will be the continuation of confrontation on the ground."

Israel is weighing a unilateral ceasefire three weeks into its onslaught against Hamas militants in the Gaza Strip that has killed more than 1,150 Palestinians and wounded over 5,000.

Egypt has been trying to broker a ceasefire deal between Israel and Hamas as the two sides do not negotiate directly.

On Friday exiled Hamas leader Khaled Meshaal called Israel's ceasefire terms unacceptable. Demanding an end to the punitive Israeli blockade of Gaza, he said Hamas would fight on.

Hamas offers a one-year, renewable truce on condition that all Israeli forces withdraw within a week and that all the border crossings with Israel and Egypt are opened.

Israeli Prime Minister Ehud Olmert's security cabinet was due to meet on Saturday evening and political sources said ministers might decide whether to halt the fighting without concluding any deal with the Palestinian Islamist movement that controls Gaza.

Israel launched an air blitz on Gaza on Dec. 27 and sent in ground forces a week later. Ten Israeli soldiers and three civilians, hit by rockets fired from Gaza, have been killed during the campaign. (Writing by Yara Bayoumy; Editing by Louise Ireland)

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