Cairo: Arab League Foreign ministers have asked for UN support in their efforts to resolve the Syrian crisis and decided to extend their observer mission.

"We will inform the United Nations of all the resolutions of the Arab League... for its approval," Qatari premier Sheikh Hamad bin Jassim Al-Thani said on Sunday in a statement after the ministerial meeting that lasted about five hours.

A decision was also taken to extend the observer mission -- despite the widespread criticism, mostly from the Syrian opposition, over its failure to stem the bloodshed -- and to increase the number of observers, he added.

The League's secretary general Nabil al-Arabi, who attended the news conference, explained that the request to support the United Nations was designed to "give more weight" to the Arab initiative aimed at resolving the Syria crisis.

The League statement called on Assad to delegate "powers to the vice president to liaise with a government of national unity," to be formed in two months.

The Arab Foreign ministers urged "the Syrian government and all the opposition factions to engage in a serious dialogue under the auspices of the Arab League, within a period of not more than two weeks, to be able to achieve the formation of a unity government bringing together those in power and the opposition."

The ministers also tasked the bloc's secretary general with nominating a "special envoy" to Syria in charge of following developments in the country.