"There is agreement on the need for the rapid resignation of President Bashar al-Assad," Sheikh Hamad bin Khalifa Al-Thani told journalists following a ministerial meeting of the Arab League in Doha which wound up in the small hours Monday.
The Arab League also urged the rebel Free Syrian Army to form a transitional government of national unity.
"We call on the opposition and the Free Syrian Army to form a government of national unity," Sheikh Hamad said as he delivered the results of the Arab League meeting.
He urged Assad to take the "courageous" decision in order to save his country where fierce fighting raged on Sunday between government troops and rebels.
Nationwide, 123 people were killed in violence on Sunday, 59 of them civilians, the Syrian Observatory for Human Rights said. It added that over the past seven days as many as 1,290 people have been killed, three quarters of them civilians.
Sheikh Hamad said Assad "could stop the destruction and the killings by taking a courageous decision".
He added that only one Arab League nation had expressed reservations over the adopted position.
Those meeting in Doha Sunday also agreed to offer $100 million in aid to Syrian refugees, said Sheikh Hamad who is also his country`s foreign minister.
At the opening of the meeting, Sheikh Hamad said that UN-Arab League envoy Kofi Annan should be given the job of drawing up a transitional policy on Syria after the failure of his peace plan to end the bloodshed.
Annan`s mission "must change", he insisted, with the emphasis now on "a peaceful transfer of power" in Syria.
The Doha meeting took place as Syrian forces, backed by helicopter gunships, launched a new assault Sunday on rebels in Damascus while fighting also raged in Syria`s second city Aleppo.
The rebel Free Syrian Army`s military council head General Mustafa al-Sheikh told AFP that "a real war of attrition" was underway in Damascus, with the Assad regime collapsing.
Fighting has intensified since a Wednesday bombing that killed national security chief General Hisham Ikhtiyar, Defence Minister General Daoud Rajha, Assad`s brother-in-law Assef Shawkat and General Hassan Turkmani, head of the regime`s crisis cell on the uprising.
The Arab League`s ministerial committee on Syria brings together Saudi Arabia, Egypt, Sudan, Algeria, Iraq, Kuwait and Oman.