"No one doubts… that al-Nusra and al-Qaeda are terrorists and that terrorists identified by the UN need to be defeated… Indeed, the estimates of the al-Qaeda, al-Nusra, whatever name they want to call themselves, are more of less around 10,000 of them plus families," de Mistura told reporters.
He also expressed his readiness to cooperate with the Syrian government to ensure the safe evacuation of civilians from the Idlib province.
"I am once again prepared, personally and physically, to get involved… with the government cooperation… to ensure such temporary [humanitarian] corridors would be feasible and guaranteed for the people so they can then return to their own places untouched," the UN Special Envoy added.
Idlib province is one of Syria's de-escalation zones and a remaining stronghold of insurgency in the war-torn country.
*Al-Qaeda and Nusra Front are terrorist groups, banned in Russia