"Aren't these oppressed Palestinians Arabs? So, when should the capacity of the Arab League be used? The Arab League should act quickly," he said.
The Iranian leader also criticised the United Nations' response to the assault on Gaza.
"To which nations does this UN belong? This security council is for the security of which part of the world?" he said.
At the opening of the Cairo meeting, Amr Moussa, general secretary of the Arab League, called for an immediate meeting of rival Palestinian factions, including Hamas and Fatah.
"I think the need for the organisation of an Islamic position is long overdue and one of an Arab League position is also overdue"
Prince El Hassan Bin Talal of Jordan
However, expectations were extremely low that the summit would achieve a major breakthrough in the crisis.
Nisreen Al Shamayleh, reporting from Cairo for Al Jazeera, said that despite widespread protests across the Arab world it was unlikely that the league would agree a concrete response.
"We have seen strong reaction from the Arab street and strong condemnation of the Israeli attacks and Arab inaction and silence," she said.
"Many people believe it shouldn't have taken 390 Palestinian casualties and 2,000 Palestinian injuries for the Arab ministers to get together."
She said the outcome of the meeting could echo the league's emergency summit on the war in Lebanon in 2006, which failed to lead to a concrete response.
Jordan's Prince El Hassan Bin Talal told Al Jazeera he believed that action from league members was "overdue" and that more demonstrations would be held across the Arab world in protest against Israel’s bombardment of the Gaza Strip.
"I think the need for the organisation of an Islamic conference position is long overdue and one of an Arab League position is also overdue," he said.
Meanwhile, Recep Tayyip Erdogan, the Turkish prime minister, arrived in Syria at the start of his diplomatic tour of the region.
Rula Amin, Al Jazeera's correspondent in Damascus, said: "It is pretty ironic that more than 22 countries are meeting and expectations are very low that they will do anything to help and now all hopes are pinned on the Turkish prime minister."