UN Special Envoy Staffan de Mistura (Photo: Reuters)

De Mistura told a news conference that he will report to UN Secretary General Antonio Guterres on Wednesday and to the UN Security Council on Thursday. He said his successor, Geir Pefersen, will take office on January 7.

The formation of a constitutional committee was agreed at the Syrian Congress of National Dialogue in Russia earlier this year. It is expected to strengthen the UN-sponsored peace process in Syria and pave the way for Syria to organize presidential and parliamentary elections.