Palestinian officials were gathering in Cairo on Sunday amid hopes of bolstering a ceasefire in Gaza, even as Israel threatened to strike at Hamas after Gaza militants fired rockets into Israel. Egypt has been mediating a truce after Hamas and Israel announced ceasefires on January 18, ending a devastating 22-day war that killed more than 1,330 Palestinians and 13 Israelis.

An advisor to deposed Prime Minister Ismail Haniya, who heads the Hamas government in Gaza, told AFP that the group was awaiting Israel's response to an Egyptian truce proposal. "We can speak with details about the truce after our delegation examines the Israeli response," said Ahmad Yusef, adding that Hamas expected the response by Monday. "But for now, things are moving in a positive direction."

A Hamas team from Gaza was already in Cairo, as was Palestinian President Mahmoud Abbas, while representatives of Hamas' Syria-based leadership were due on Monday, a Hamas official said.

Abbas was scheduled to travel to Prague to meet his Czech counterpart, Vaclav Klaus, but announced on Saturday that he would travel to Cairo instead, where he would meet Egyptian President Hosni Mubarak on Monday. Abbas came to Egypt after Egyptian officials relayed "optimistic reports" from meetings with Hamas, Fatah official Nabil Shaath told AFP.

"Our Egyptian brothers reported to us what they feel to be a more open and therefore more optimistic position [from Hamas]," he said. "What Egypt will say to us tomorrow will be very important."

However, Abbas on Sunday ruled out talks with any group which does recognize the PLO's legitimacy, in a reference to Khaled Meshaal, political chief of Hamas.

"We say this with utmost clarity: no dialogue with whoever rejects the Palestine Liberation Organization," Abbas said at a news conference in the Egyptian capital.

Meshaal, who heads Hamas' politburo from exile in Syria, said last week that the PLO had become obsolete and called for "a new, national authority."

Hamas beat Fatah in parliamentary elections in 2006.

Meshaal, who was visiting Iran, repeated on Sunday that Hamas would not accept a permanent ceasefire with Israel until it ended its blockade of Gaza.

Israel imposed its siege of the impoverished Gaza Strip following the Hamas victory in the 2006 polls. The Zionist state further tightened its grip after the Islamists took power in Gaza by force in 2007.

"While the occupation continues, a permanent ceasefire has no meaning," Iran's official Islamic Republic News Agency quoted him as saying during a joint news conference with Iranian Foreign Minister Manouchehr Mottaki.

Meshaal, who arrived in Iran earlier on Sunday for his first visit since the war, said the Gaza blockade was a key "priority." "While the blockade continues, we believe the aggression [by Israel] continues," he added.

Later Sunday Meshaal met Iran's supreme leader, Ayatollah Ali Khamenei, who urged him to be prepared for any situation even a "new war" with Israel, the semi-official news agency ISNA reported.

"The Islamic resistance has to be careful and prepared for any situation even the possibility of a new war," Khamenei was quoted as saying.

The fragile ceasefire has been tested by tit-for-tat attacks which flared up after Israeli raids in the territory and after Palestinian militants detonated a roadside bomb at the Gaza border with Israel, killing a soldier. Palestinian fighters have also fired at least seven rockets at Israel, as well a mortar round on Sunday that slightly wounded two people.