Arab nations have called on Syrian President Bashar al-Assad to swiftly give up power as his troops launched a fresh assault on rebels in Damascus and the second city Aleppo, according to AFP.

Fighting raged Sunday, July 22 despite claims by the rebel Free Syrian Army that Assad's regime was "collapsing".

In a joint statement issued early Monday after their meeting in Doha, Arab League foreign ministers called on Assad to "renounce power," promising that he and his family would be offered "a safe exit".

"There is agreement on the need for the rapid resignation of President Bashar al-Assad," Qatar's Prime Minister Sheikh Hamad bin Khalifa Al-Thani told journalists after the Arab League meeting wound up in the small hours Monday.

The Arab League called on the Free Syrian Army rebels and the opposition to form a transitional government of national unity along with the "de facto national authority", without detailing who that authority might be.

The Arab nations also called for an extraordinary meeting of the UN General Assembly to work towards creating "security zones" and "humanitarian corridors" in Syria.

The United States declared Sunday that it would "hold accountable" any Syrian official involved in the release or use of the country's chemical weapons.