UNITED NATIONS, June 27 (Xinhua) -- Staffan de Mistura, the UN special envoy for Syria, on Wednesday warned the Security Council that a full-scale battle in the country's previously calm south-west could engulf an area and population the size of eastern Ghouta and Aleppo combined.

Briefing delegates from Geneva, de Mistura said that over the last week, nearly 50,000 people in the south-west had been displaced by a full ground offensive, aerial bombardments and exchanges of gunfire from both sides.

The implications raised significant risks for regional security and compromised progress being made on the political front, which was focused on the formation of a constitutional committee.

He said that this month, he had consulted with France, Germany, Jordan, Saudi Arabia, the United Kingdom and the United States on de-escalation arrangements, as those countries had a stake in the process and could be important players in any reconstruction.

De Mistura had also sought to advance the Final Statement agreed at the Syrian Congress of National Dialogue, held in Sochi, Russian Federation.

He had received a list of 50 nominees for the constitutional committee from Syria and was awaiting a similar one from the opposition.

"We are moving cautiously in the right direction," he said, urging the Council to help find a solution in the south-west that would spare suffering and reduce displacement.

The special envoy urged all parties to use existing channels for the protection of civilians and for providing an exit to the conflict.