UN-Arab League envoy Lakhdar Brahimi said Sunday no firm date has been set for Syria peace talks, which are in doubt in part because of rifts among the opposition.

Arab League chief Nabil al-Arabi said the conference would be held November 23, but UN officials have said Secretary General Ban Ki-moon will decide the date of the meeting and who is invited, and Brahimi said no such date had been set.

"There are many difficulties that must be overcome for this conference to succeed," Brahimi said at a Cairo press conference after meeting Arabi.

"There is an agreement to attempt to hold Geneva 2 in November, but the date has not been officially set," Brahimi said, speaking on the first leg of a regional tour aimed at garnering support for the talks.

"The final date of the conference will be announced at a later time... and we hope it will take place in November."

Both officials acknowledged there were still obstacles to holding the conference, as Western and Arab diplomats prepare to meet Syrian opposition leaders on Tuesday to attempt to persuade them to attend.

"The conference will not convene without a credible opposition representing an important segment of the Syrian people opposed (to President Bashar al-Assad)," Brahimi, a veteran Algerian diplomat, said.

Last week Syria's deputy prime minister said peace talks could be held November 23-24, but a spokesman for Ban said the secretary general would make the official announcement and decide which parties would attend.

The renewed push for peace talks comes after a rare US-Russian accord compelled Syria to agree to destroy its chemical arsenal, but much of the opposition panned the deal because it averted punitive US strikes on the regime.

The main National Coalition opposition bloc said members will decide in the coming days whether to attend the Geneva talks, while the Syrian National Council, a key coalition member, has threatened to quit if they do.

Brahimi told reporters after his meeting with Arabi that he would travel to Qatar, Turkey, Iran, Syria and then to Geneva for talks with Russian and US representatives.