DAMASCUS: Pressure mounted Tuesday on Syrian President Bashar Assad to respond to a surprise offer of talks with his main political opponents, while Islamic nations were expected to call for dialogue as they meet in Cairo Wednesday.

Assad himself has yet to comment on the offer from Ahmed Moaz al-Khatib, leader of the opposition National Coalition, who said Monday that “the ball is now in the regime’s court. They will either say yes or no.”

He was following up on his announcement last week that he was ready for talks with Assad’s regime – subject to conditions that include the release of 160,000 detainees – on ending the conflict that has ravaged Syria for nearly 23 months.

Khatib later elaborated, saying he was ready to meet Assad’s deputy, Vice President Farouk Sharaa.

But the proposal appeared to suffer a blow Tuesday, when both a ruling party lawmaker and the largest bloc inside the anti-regime coalition rejected the idea.

Syrian Parliamentarian Fayez Sayegh told the Associated Press that any dialogue must begin without preconditions. He also called Khatib’s estimate of the number of opposition supporters in Syrian custody “exaggerated,” although he did not give an alternate figure.

“What is important is for Syrians to meet and agree on common ground for talks,” Sayegh said, adding that Khatib’s proposals, such as the prisoner release, should come “as a result of a dialogue, not before it begins.”

The Syrian National Council, the main component of the opposition coalition, also refused to countenance the possibility of holding any talks, saying it was committed to ousting the regime without dialogue and protecting the revolution.

In the past the opposition has demanded Assad step down before talks can begin, but analysts say Khatib’s change in stance stems from a belief the population will be bled dry while the West fails to act.

Experts have also predicted Damascus would reject Khatib’s overture outright, and hinting at this, the pro-regime Al-Watan newspaper said Tuesday that Khatib’s offer had come too late.

“Despite their importance, the statements of Sheikh Moaz al-Khatib are two years late,” the paper said in an editorial. “During that time, our finest young men have died, suffered wounds or been exiled, while we have lost our electricity and fuel infrastructure, alongside several military positions.”

“So the ball is not in the Syrian state’s hands, as Khatib said,” Al-Watan added.

Arab League chief Nabil Elaraby threw his weight behind Khatib’s offer, however, and offered to play a role in any negotiations for a democratic transition in Syria.

Elaraby was speaking ahead of a meeting of leaders of Islamic Nations in Cairo starting Wednesday that will call for dialogue between the Syrian opposition and government officials “not involved in oppression.”

According to a draft communique seen by Reuters Tuesday, the declaration does not mention President Bashar Assad and pins most of the blame on his government for continued violence. The document is due to be issued after the two-day summit of the 56-member Organization of Islamic Cooperation.

“We strongly condemn the ongoing bloodshed in Syria and underline the Syrian government’s primary responsibility for the continued violence and destruction of property,” the draft communique said.

It was not clear whether Syria’s ally Iran, which is attending the OIC summit, would back the tough wording.

However, Khatib made his offer of talks after groundbreaking meetings with the foreign ministers of Russia and Iran, Assad’s two main allies, at a security conference in Germany.

The U.S. strongly backed Khatib’s call for dialogue, with the State Department saying the regime “should sit down and talk,” while stressing its position was unchanged on bringing to account those who have committed atrocities.

Assad announced last month he was ready for talks with the opposition but ruled out meeting groups such as the National Coalition, which backs rebels seeking to overthrow his regime.

Khatib’s controversial proposal has divided Assad’s opponents. While some figures have criticized the offer, others say it could expose Assad’s proposals for dialogue as hollow.

Coalition members have called for an emergency meeting to discuss the move.

“The coalition needs to convene to chart an urgent strategy after the reverberations of the initiative and seize on the momentum it has created, regardless of the reservations of some members,” one coalition official said.

“The initiative is proving to the international community that Assad is not willing to compromise one millimeter, and we need to take advantage of that.”

Thirty members of the coalition have sent a letter to its leadership demanding an urgent meeting for the whole assembly, according to coalition sources.

Fresh violence meanwhile erupted Tuesday in the northern city of Aleppo, where rebels clashed with troops near an army barracks, the opposition Syrian Observatory for Human Rights said.

Army tanks also shelled the districts of Qadam and Assali on the outer edges of Damascus, the Britain-based group added.

Syrian rebels and Jordanian security officials also cited intense fighting near Syrian government installations and border posts near Jordan, leaving 17 civilians wounded.

The U.N. says more than 60,000 people have been killed in violence across Syria since the outbreak of a revolt in March 2011 that morphed into an insurgency after the army launched a brutal crackdown on dissenters.