Hamas leader Khaled Mashaal rejected Israel's conditions for a Gaza cease-fire and demanded an immediate opening of the territory's borders, taking a tough line Friday as he asked Arab countries to back him by cutting off any ties with Israel. Mashaal spoke at a summit of Arab leaders in the Qatari capital that only underlined how the now three-week-old Gaza offensive has deepened the split in the Middle East between pro-US governments and their rivals, particularly Hamas's allies Syria and Iran. Pro-US Egypt and Saudi Arabia boycotted the gathering, fearing it would become a platform for Hamas to boost a hard-line position and would undermine Egypt's attempts to mediate a cease-fire between the Palestinian militant movement and Israel. In Cairo, Amos Gilad, the head of the Defense Ministry's Diplomatic-Security Bureau, held talks with Egyptian officials for a second straight day Friday on a cease-fire proposal put forward by Egypt. An Egyptian security official, speaking on condition of anonymity due to the sensitivity of the talks, said "signs are encouraging" for a breakthrough" in negotiations over a cease-fire. Iranian President Mahmoud Ahmadinejad made a surprise appearance at the Doha gathering - strengthening the image that the summit was a show of backing for Hamas. In a speech to the summit, Syrian President Bashar Assad backed Mashaal's call for those Arab countries with any ties to Israel to cut them. Much as Egypt feared, Mashaal sought Arab support in a strongly worded address to the summit, insisting Hamas cannot stop fighting until border crossings into the Gaza Strip are opened. The stance undermines a cease-fire proposal that Egypt is trying to mediate. Under the Egyptian proposal, fighting would stop immediately for 10 days, but IDF troops would remain in place in Gaza and the borders would remain closed, until security arrangements are made for the crossings to ensure Hamas does not smuggle weapons into the territory. Israel demands a halt to Hamas rocket attacks into southern Israel and internationally backed guarantees that Hamas will not rearm by smuggling weapons into Gaza. "We will not accept Israel's conditions for a cease-fire," Mashaal told the summit. He said Hamas demands that "the aggression stop," Israeli troops withdraw and crossings into Gaza be opened immediately. He insisted that Israel was to blame for the Gaza conflict. Mashaal set down Hamas's view of the conflict, trying to fend off suggestions from Egypt and Saudi Arabia that its rocket attacks were to blame for sparking the Israeli assault. Mashaal said Hamas refused to renew a six-month-old truce with Israel that ran out in December because the period of relative calm had not led to an end of the Gaza blockade. "Did we do wrong, by rejecting a truce that let the blockade continue?" Mashaal said. "Don't the people of Gaza deserve to live free? ... They want to live free without blockade or occupation, just like all the Palestinian people do." "Please listen to the voice of the resistance," he said. "Don't think that Hamas wants an open war. We are defending our people." Mashaal asked Arab countries to boycott Israel and cut off any ties with it. Egypt and Jordan, which did not attend, are the only Arab nations with diplomatic ties with Israel, but several Gulf states - including Qatar - have lower level economic ties. Like Egypt and Saudi Arabia, Palestinian Authority President Mahmoud Abbas, boycotted the Qatar gathering, and around 10 other Arab leaders also stayed away, reportedly under pressure from Cairo and Riyadh. Egypt and Saudi Arabia have instead suggested leaders discuss Gaza at a previously planned economic summit due to begin in Kuwait on Sunday. Arab foreign ministers met Friday in Kuwait to prepare for the gathering and discuss Gaza.