The United Nations is mulling "light touch" options for monitoring a possible ceasefire in Syria that would keep its risks to a minimum by relying largely on Syrians already on the ground, diplomatic sources said.

The UN Security Council on Friday unanimously called on Secretary-General Ban Ki-moon to draw up within a month options for monitoring a ceasefire in Syria. It is the second time since the Syrian civil war broke out in March 2011 that the council backed a plan for peace talks and a truce.

The talk about the UN's role as monitor has gained urgency along with a new push for a ceasefire in Syria to take effect as early as January, in parallel to talks between the government and opposition.

More than a dozen major powers, including the United States, Russia and major European and Middle Eastern powers, have drawn up a road map for Syria peace talks.

UN planning for truce monitoring will seek to avoid repeating the "disaster" of a mission sent to Syria in 2012, diplomats said. That operation failed because the warring parties showed no interest in halting the fighting, they said.

Under the light-touch mechanism under consideration, the United Nations would rely on Syrian actors - "proxies" - on the ground to report violations. This could possibly involve a small group of non-uniformed UN officials in Syria to carry out investigations of ceasefire violations, diplomats said.

"There's the idea of proxy-ism, where they were going to look at who would be credible on the ground to get information and to create a reporting mechanism from them to the UN," a diplomatic source said.

To make the proxy approach work, major powers would need to agree on who is considered a credible Syrian actor.

"Who is it who's responsible for the credibility of the information?" one diplomatic source asked. "The Syrians on the ground or the UN, which receives the information?"

The UN Department of Peacekeeping Operations will likely present an option to put UN peacekeepers on the ground. But that approach likely will be ruled out immediately, given the brutal war that has claimed more than a quarter of a million lives.

Diplomats on the council, which would be asked to approve any monitoring plan, also say that option is impossible.

"DISCONNECTED FROM REALITY"

Diplomats say they want to avoid a heavy UN footprint in Syria. A large number of UN officials on the ground in Syria would require a large security detail to protect them.

"If we have a big security contingent, all of a sudden it looks like a full-scale mission," one diplomatic source said. "And any UN presence will be targeted in Syria."

Another tool for aiding verification work, another diplomatic source said, could be the use of unmanned surveillance drones, a technology the UN has begun using in peacekeeping missions in Africa.

The UN had to suspend operations once before in Syria. After deploying some 300 unarmed "blue beret" monitors in April 2012, it was forced by August of that year to end the mission after the moderators became the target of angry crowds and gunfire. - Reuters