Japan and Sweden have requested a UN Security Council meeting to obtain specific details of a Russia-backed agreement on establishing safe zones in Syria, diplomats said Tuesday.
The meeting, which is likely to be held this week, would help council members decide on whether to endorse the deal signed by Russia, Iran and Turkey.
The agreement signed in the Kazakh capital Astana on May 4 calls for the creation of four "de-escalation zones" to shore up a ceasefire, ban flights and allow for deliveries of humanitarian aid.
The United Nations has described it as a promising step in efforts to end the six-year war that has killed more than 320,000 people.
Russia has presented a draft resolution to the council that welcomes the deal and calls on all parties to abide by its provisions, but no vote has been scheduled on the measure.
French Ambassador Francois Delattre said it was important that the council "get all the clarity needed before engaging on a draft resolution."
"The question today is: Do we have all the elements we need to understand the substance and the way this agreement is going to be implemented? This is really the key question and frankly the answer to this question is 'not yet'," Delattre told reporters.
Japan and Sweden are, along with Egypt, the leaders at the Security Council on humanitarian issues from the Syrian conflict.
Under the deal, Russia, Iran and Turkey have until June 4 to agree on the exact boundaries of the four zones, where fighting between rebels and government forces is meant to stop.
Diplomats said they wanted to see maps to clearly assess the territory that would be covered by the deal which provides for vital deliveries of humanitarian aid.
"We want to have more information," said Swedish Ambassador Olof Skoog.
The agreement has not been signed by the Syrian government or the opposition. Details on whether international monitors will be deployed to the areas remain sketchy.
Syrian Foreign Minister Walid Muallem has rejected any role by the United Nations in monitoring the designated zones.
Diplomats have raised concerns that the Astana talks will sideline the UN-brokered peace talks. UN envoy Staffan de Mistura on Monday announced that the next round of negotiations will begin on May 16.