The EU's migration chief said that forcibly returning Syrians to their home country was "not possible" for the time being, after member state Austria said it was planning to do so.

Vienna signalled this week it intended to deport refugees back to war-ravaged Syria, after an Islamist-led rebel offensive ended the Assad clan's decades-long grip on the country.

But the European Union's migration commissioner Magnus Brunner - who is himself Austrian - made clear following talks with interior ministers in Brussels that such a move would be premature.

Syrian rebel forces led by the Islamist group Hayat Tahrir al-Sham (HTS) have appointed an interim prime minister to lead Syria until March, and vowed to institute the "rule of law".

But with HTS rooted in Syria's branch of Al-Qaeda, the joy of Assad's overthrow has been accompanied by uncertainty about the future of the multi-ethnic, multi-confessional country. 

"For now, I would say forced return is not possible," Brunner told a press conference - while noting that returning home voluntarily "may be attractive for many Syrians" celebrating the end of Bashar al-Assad's brutal rule.

"As the situation is still volatile, we have to focus on these voluntary returns," Brunner said, arguing for EU support - including financial - for returnees.

"When it comes to the question of money, yes," Brunner said. "I think we have to do something."

The war in Syria - unleashed by Assad's bloody crackdown on protests in 2011 - helped spark a migrant crisis that saw more than one million people arrive in Europe in 2015.

Multiple EU nations including Malta, Germany and Italy have frozen new asylum requests by Syrian citizens in the wake of Assad's ouster, with more than 100,000 cases pending across the bloc at the end of October according to official data.