Syrian children stand outside a tent next to a metal crib at a camp for displaced civilians in the rebel-held northwestern Idlib province on Sept. 5, 2018. (AFP Photo)

UNITED NATIONS, Sept. 7 (Xinhua) -- The UN special envoy for Syria said Friday that the situation there had all the "ingredients" for a "perfect storm" with devastating humanitarian consequences, urging all stakeholders to find a solution to avert a tragedy.

Staffan de Mistura, the UN secretary-general's special representative for Syria, briefed the Security Council by videoconference on the situation in Idlib, where an eminent offensive by the Syrian forces, aided by Russia, is likely to take place.

Speaking from Geneva, he pointed to the intensified military presence and increased airstrikes in the northwestern region, which have prompted fears of a potential humanitarian catastrophe in the last rebel stronghold.

Idlib is one of the four "de-escalation zones" in Syria agreed under a deal reached last year by Iran, Russia and Turkey in Kazakhstan's capital Astana. The other three have all been violated.

The UN estimates nearly three million people are trapped there, half of whom were displaced from other parts of the country. While most are civilians, terrorist organizations, foreign fighters and armed opposition groups have also gathered in Idlib.

"I have laid out...all the ingredients for a perfect storm. The dangers are profound that any battle for Idlib could be, would be, a horrific and bloody battle," the UN envoy said, adding civilians are its potential victims, and there are ever-present dangers in the case of a full-scale assault of incidents, rapid escalations, involving regional and international players."

"The Security Council cannot accept that the civilians of Idlib must face this type of fate. Efforts to combat terrorism do not supersede obligations under international law in the moral conscience of humanity. We must put the sanctity of human civilian life above everything else."

De Mistura urged all stakeholders in the crisis to find a solution to prevent a tragedy in Idlib while also addressing the issue of terrorism.

The three "Astana guarantors" -- Iran, Russia and Turkey -- met in Tehran on Friday and de Mistura will hold talks with them in Geneva starting Monday.

He will also meet with representatives from Egypt, France, Germany, Jordan, Saudi Arabia, Britain and the United States later in the week.

"It would be the ultimate failure of imagination and of diplomacy if, with these efforts, we simply saw an increase of military activities," he said.