Syrian President Bashar Al-Assad
Syrian President Bashar Al-AssadReuters

Syria's opposition has rejected a proposal from UN envoy Staffan de Mistura that would have kept Bashar Al-Assad as president during a political transition, with three deputies of his opponents' choosing, AFP reported Saturday.

De Mistura told Syria's opposition attending peace talks in Geneva that the proposal could end the "vicious cycle" of debate over a transitional period to end the war, a source told the news agency.

On the ground, tens of thousands of Syrians are at risk of being displaced as clashes between rebels and jihadists intensified in the country's north.

The escalating fighting across swathes of Aleppo province has threatened to collapse a fragile ceasefire and derail the latest round of indirect negotiations in Switzerland between the regime and opposition.

The fate of Assad remains the key sticking point in the discussions involving the opposition High Negotiations Committee (HNC) and a government delegation.

The HNC is demanding he leave power – dead or alive – before any transitional government is agreed.

The regime says the president's future is not up for discussion.

A HNC source told AFP on Saturday that the committee had rejected a proposal by de Mistura that would have seen Assad remain as president through a transitional period.

In exchange, the HNC would have been allowed to hand-pick three vice presidents, the source said on condition of anonymity because he was not authorized to speak to the press.

Assad "would transfer his military and political prerogatives to them. Effectively, Assad would stay in a ceremonial position."

"But we categorically rejected the proposal," he said.

Assad's ouster has been the key demand of Syria's opposition since the uprising broke out in March 2011, but Damascus says his departure is not on the table.

While the opposition insists on forming a "transitional governing body" without Assad, the regime says it wants to form a broader "unity government."

The HNC source said de Mistura had presented the idea of Assad transferring most of his powers to three deputy presidents from the opposition as a way to end that "vicious cycle" of debate.

According to him, de Mistura told the opposition that the proposal "was not his personal view... but that he hoped to hear our thoughts".

On Friday, HNC spokesman Salem al-Meslet told AFP that Syria's opposition would be willing to cooperate with regime "diplomats and technocrats" in a transitional period.

But he insisted that there would be no role for Assad or anyone who had played a central role in the civil war, which has killed 270,000 people and displaced millions.

AFP contributed to this report.