Iraqi Foreign Minister Hoshyar Zebari welcomes Algeria's Foreign Minister Mourad Medelci in Baghdad, Iraq, Tuesda (Photo: AP)
The gathering in the Iraqi capital comes as monitors reported that Syrian forces stormed the central Syria town of Qalaat al-Madiq, and as China urged Syria's government and opposition to honour commitments to halt armed conflict.
"The Syrian subject will have a significant place in discussions," Arab League Secretary General Nabil al-Arabi said of Wednesday's meeting, adding: "I think that the ministers' meeting ... and the Arab summit will support" the plan of Annan, the UN-Arab League special envoy to Syria.
Annan's deputy Nasser al-Qudwa was also due in Baghdad to brief foreign ministers "on the latest from Kofi Annan's deliberations," Iraq's Deputy Foreign Minister Labid Abbawi said.
A draft resolution due to be debated by the foreign ministers in Baghdad on Wednesday calls on the "Syrian government and all opposition factions to deal positively with the envoy (Annan) by starting serious national dialogue."
It also urges the regime to "immediately stop all actions of violence and killing, protect Syrian civilians and guarantee the freedom of peaceful demonstrations for achieving demands of the Syrian people," according to a copy of the text obtained by AFP.
Iraqi Foreign Minister Hoshyar Zebari has said, however, he does not think Arab leaders will call on Assad to step down when they hold their Baghdad summit on Thursday.
With international pressure mounting on Assad to end a crackdown on dissent that the UN says has left more than 9,000 people dead in the past year, Syria's opposition groups agreed in Istanbul late on Tuesday to name the Syrian National Council as their sole representative.
They also called on Assad to pull back his tanks to show he was serious about peace. Annan's plan includes calls for a daily two-hour humanitarian ceasefire and access to all areas affected by the fighting in Syria.
Western powers cautiously welcomed Assad's reported backing of the Annan plan but US Secretary of State Hillary Clinton said this had to be backed up with rapid action. "Given Assad's history of over-promising and under-delivering, that commitment (to Annan) must now be matched by immediate actions," Clinton told reporters ahead of Sunday's "Friends of Syria" meeting in Istanbul.
Sunday's gathering will bring together Arab countries and Western powers to discuss the crisis after Syria's opposition factions took a step towards unity late Tuesday.
"The conference decided that the SNC (Syrian National Council) is the formal interlocutor and formal representative of the Syrian people," said a statement read to journalists after two days of talks in Istanbul.
Most opposition factions present signed the statement, and challenged Assad to prove he was serious about peace.
"If he is really serious he must apply this initiative tomorrow," said opposition leader Waid al-Buni. "Tomorrow, there must not be any tanks in the streets and the Syrian regime militaries should be withdrawn.
"Tomorrow, the Syrian people must be capable of taking the streets by millions. So tomorrow we will see if the regime is really honest."
Annan held talks in Beijing on Tuesday with Chinese Premier Wen Jiabao, who pledged his support for his mediation efforts, as did Russian President Dmitry Medvedev when the ex-UN secretary general visited Moscow over the weekend.
China and Russia -- both allies of Syria -- have provoked Western fury by twice blocking UN Security Council resolutions that condemned Assad's regime.
Chinese foreign ministry spokesman Hong Lei told reporters in Beijing on Wednesday that China was "happy" that Damascus had backed the Annan plan and urged both Syria's government and opposition factions to honour their commitments to end the conflict.
"We are happy to see the Syrian government has accepted the six-point proposal of special envoy Annan, and believe it will be conducive to the political settlement of the Syrian issue," he said.
"We hope the Syrian government and relevant parties in Syria will honour their commitments," he told journalists at a regular briefing.
On the ground, Syrian forces backed by tanks stormed the central town of Qalaat al-Madiq and nearby villages on Wednesday after a siege lasting more than two weeks, the Syrian Observatory for Human Rights said.
The Britain-based monitoring group said the troops entered the town, in Hama province, just after dawn following a 17-day barrage of shelling and heavy gunfire to root out rebels. It added however that the army was not in control of the town.
The army's offensive is part of the regime's efforts to overrun rebel strongholds as it tries to crush an unprecedented revolt. Fierce clashes were also reported on Wednesday in the southern province of Daraa, cradle of the year-long revolt, the Observatory said.