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

The UN envoy to Syria on Wednesday invited Syrians to take part in what he called "thematic" discussions to keep alive stalled efforts to negotiate an end to the war.

"Sadly there is still no consensus on the way forward," Staffan de Mistura told the UN Security Council after two months of meetings with key players in the conflict.

"The UN is obliged and all of us are obliged to keep the issue alive," added the Swedish-Italian diplomat, appointed last year to what many termed "mission impossible."

Proposed discussions would focus on protecting civilians, political and constitutional issues, military and security issues, public institutions and reconstruction.

"Such an international initiative will require the support of a contact group and we will get to that at the right time."

De Mistura's predecessors - hugely respected diplomats Kofi Annan and Lakhdar Brahimi - both resigned after failing at the task of trying to bring peace to the country.

UN Secretary General Ban Ki-moon said Wednesday that he was "profoundly disappointed" that Security Council resolutions had failed to bring an end to the violence or ease the suffering.

At least a quarter-of-a-million Syrians had been killed and nearly half the population - 12 million men, women and children - have been forced to flee their homes by the fighting, he said.

AFP contributed to this report.