Syria signed the Arab League (AL) observer deal on Monday in Cairo, an Arab League official told Xinhua.

The protocol was signed by AL Deputy Secretary General Ahmed Ben Helli and Syrian Deputy Foreign Minister Faisal Mekdad.

The AL is to hold a meeting in Cairo on Tuesday at the level of permanent delegates to discuss the latest situation in Syria.

The signing came after the AL threatened at a meeting on Saturday to submit the Arab initiative to the UN Security Council.