UN Special Envoy for Syria Staffan de Mistura
UN Special Envoy for Syria Staffan de MisturaReuters

The UN's peace envoy for Syria on Tuesday launched wide-ranging consultations in Geneva with regional and domestic players, including Iran, in a bid to revive stalled talks to end the conflict.

Staffan de Mistura said talks with the Syrian government and some 40 groups, including "political, military actors, women, civil society, victims, the diaspora", would also rope in some 20 regional and international players, according to the AFP news agency.

Iran, a key player in the conflict, had been excluded from the stalled Geneva I and Geneva II peace deals. The current dialogue will also include the five permanent members of the UN Security Council.

The consultations would be held on a one-to-one basis between the UN and the separate players. De Mistura's first meeting was with Syrian ambassador to the UN in Geneva Hussam Eddin Ala, noted the report.

He said though "low-key", the talks would be "very serious" and could extend beyond a tentative end-June deadline.

"There is no cut-off date," the Swedish-Italian diplomat said, adding, "By the end of June we will assess progress... and decide on the next steps."

The talks could help determine "whether another round of negotiations is feasible down the line, and what a future peaceful Syria may look like," he said.

Terror-listed entities like the Islamic State group and the Al-Qaeda-affiliated Al-Nusra have not been invited but groups in contact with them are on the list of participants.

De Mistura refused to divulge the identities of the military or other groups he would be talking to.

"We will try to listen to the maximum voices," he said, according to AFP.

"They also include broad representation of the civil society as this process has to speak to the voices of the Syrian people who often are not heard enough.

"This process will be expanded to others as we move along," he said.

"The UN will never abandon Syria even if it looks like Mission Impossible," de Mistura stressed, voicing his "determination" to help find a solution to end the crisis.

Calling the Syrian conflict the "biggest humanitarian tragedy since the Second World War," de Mistura said he would "leave no stone unturned" in his bid to try and end the fighting.

The launch of the dialogue comes as rights group Amnesty International accused government forces of crimes against humanity by indiscriminately bombing the country's former economic powerhouse Aleppo. It also criticized rebels for abuses including war crimes.

De Mistura said the dialogue would be a "stress test as you do with banks" to try and answer the question "What is the situation today?"

De Mistura is the third UN envoy to tackle Syria's conflict, which began in March 2011 with peaceful anti-government protests and descended into a war after a harsh regime crackdown.

He has already angered rebel groups by saying  Assad was as "part of the solution" to the conflict in Syria.

In response to those comments, rebels in Aleppo rejected de Mistura’s proposal for a temporary ceasefire in the city.