"There is still a chance to stop the spilling of blood before it's too late. This is not a time for arrogance," Morsi said during the Cairo summit. "The Syrian people have said their word; it's time to give them their demanded change now."
Syrians opposed to the Assad regime, loosely organized under the banner of the Free Syrian Army, have been fighting against government forces for the last 18 months in an increasingly bloody showdown that has claimed over 20,000 lives.
In calling for Assad's resignation, Morsi is siding with a growing chorus of international voices, from Western nations like France and the United States to Sunni Arab states like Saudi Arabia and Qatar. He is also taking a stand against Iran, a majority Shia state and the strongest ally of the Syrian regime.
This underscores the growing importance of Sunni Egypt's relationship with the West, calming fears the newly-elected Morsi, of the Islamist Muslim Brotherhood, might shun the U.S. alliance that has defined Egyptian diplomacy for the past 30 years.
On Wednesday, Morsi suggested that Assad should learn the lessons of "recent history," a likely reference to the Arab Spring revolutions that have resulted in the overthrow of several dictatorial leaders across the Arab world -- including Morsi's own predecessor, Hosni Mubarak.
"There is still a chance to stop the bloodshed," Morsi added, addressing Assad. "There is no room for stubbornness. Don't listen to the voices that tempt you to stay."
Meanwhile, Syria's struggle continues. On Thursday, reports the Associated Press, regime troops backed by 20 tanks seized Tel Chehab, a formerly rebel-controlled town on the border with Jordan, in an apparent attempt to stop more Syrian refugees from crossing the border. More than 100,000 refugees fled the country during the last month alone.