By Stephanie Nebehay, John Irish and Suleiman Al-Khalidi
GENEVA (Reuters) - The United Nations said on Thursday it would tackle the divisive issue of a transition in Syria when warring parties meet again next month after outlining a common blueprint for a political process that could end the five-year civil war.
With a fragile ceasefire in place, the indirect "proximity talks", with government and opposition delegations in separate rooms, adjourned on Thursday after almost two weeks of discussions and aim to reconvene from around April 9.
The talks are part of a diplomatic push launched with U.S. and Russian support to end a conflict that has killed more than 250,000 people, created the world's worst refugee crisis and aided the rise of Islamic State.
"I am expecting and hoping ... that the next round of talks will not be focusing on principles again - we have had enough of that - there are many valid points there, but we have to start focusing on the political process," U.N. Syria special envoy Staffan de Mistura told reporters.
De Mistura is sticking closely to a peace plan endorsed by the U.N. Security Council in December calling for a Syrian-led process that establishes "credible, inclusive and non-sectarian governance", a new constitution, and free, fair elections within 18 months.
But while all sides attending the talks have committed to a political transition that will follow the war, progress has been slow with the Syrian government delegation and its opponents disagreeing fundamentally on what that means, including whether President Bashar al-Assad must leave power.
"We come out with feeling that we have perhaps laid the basis for substantive talks," opposition negotiator Basma Kodmani said. However, she cautioned that much would depend on Russian leverage over the Syrian government in the coming weeks.
After meeting European Union foreign policy chief Federica Mogherini on Wednesday, a rare encounter with a senior Western figure, government negotiator Bashar Ja'afari sounded positive saying he thought a diplomatic impasse has been broken.
Damascus, he said, would now review the U.N. document before the talks resume.
"These are guiding principles. We are not getting into the details of what is the mother of all issues, the political transition, political process," de Mistura said.
He said there was reference to the 2012 Geneva Communique and to resolution 2254 which includes three elements - governance, constitution and elections.
The De Mistura document contains points including reforming state institutions according to international criteria, rejecting terrorism unequivocally and implementing resolution 2254 that guarantees a political transition of power.
It also calls for no tolerance of acts of revenge from either side, rebuilding the Syrian army on national criteria, ensuring a democratic non-sectarian state and preserving women’s rights in fair representation.
De Mistura said that none of the sides had refused the principles.
"The next round will be a more difficult session for de Mistura. In my view it's make or break," said a senior Western diplomat.
De Mistura aims to reconvene the talks on April 9, although some parties may come as late as April 14, a day after parliamentary elections in Syria.
(Additional reporting by Tom Miles; editing by Ralph Boulton)