Najib Ghadbian, the Syrian National Coalition's (SNC) envoy to the United Nations, said opposition groups need "a month or so" to prepare for political talks that would begin in tandem with a ceasefire.

"I don't think those timetables are realistic," Ghadbian told reporters.

He spoke as foreign ministers from 17 countries were meeting in New York to push forward on a plan to launch a political transition that will end Syria's nearly five-year war.

At their last meeting, the nations set a target date of January 1 to launch intra-Syrian talks and a ceasefire.

A key issue for the SNC is whether the ceasefire will apply to Russia's air campaign, which began in late September in support of President Bashar Al-Assad.

"Russian attacks continue to target everything and anything but ISIS," said Ghadbian, referring to the Islamic State group that now controls large parts of Syria.

Russia maintains that it launched its air campaign to fight IS jihadists, but the West accuses Moscow of targeting its armed allies in the war.

The UN-brokered ceasefire would apply to Syrian government forces and all other factions on the ground, except for the IS group, in a major step toward ending the violence that has left 250,000 dead.

Ghadbian stressed the close link between the ceasefire and the political talks, saying that armed groups will move away from the battlefield only if political negotiations have a chance for success.

The envoy said he would welcome a Security Council resolution endorsing the Syrian peace process, that was being negotiated on Friday and could be adopted during the day.

He said the resolution would provide "guarantees" that the political talks with the Damascus regime on a transition will be taken more seriously after the failure of two previous UN rounds of talks.

Syria regime, Russia making 'extensive' use of cluster munition: HRW
Beirut (AFP) Dec 20, 2015 - Human Rights Watch charged Sunday that Syrian government forces and their Russian allies have been making "extensive" use of cluster munitions against rebel groups since late September.

The New York-based rights watchdog said in a report it had documented the use of cluster munitions on 20 occasions since Russian and Syrian forces launched their assault on September 30.

HRW "collected detailed information about attacks in nine locations that have killed at least 35 civilians, including five women and 17 children, and injured dozens", the report said.

All the bombs were either made in Russia or the former Soviet Union, the rights group said.

"Syria's promises on indiscriminate weapons ring hollow when cluster munitions keep hitting civilians in many parts of the country," HRW's Ole Solvang said in the report.

Solvang urged the UN to "get serious about its commitment to protect Syria's civilians by publicly demanding that all sides stop the use of cluster munitions".

Syrian army makes strategic gain in north
Damascus (AFP) Dec 20, 2015 - The Syrian army, backed by Russian air strikes, captured a rebel stronghold in the northern province of Aleppo on Sunday, driving out the Islamists, a monitoring group said.

State news agency SANA also said that army units and other pro-regime forces had seized control of Khan Tuman and neighbouring farms.

Khan Tuman was the scene of fierce clashes between loyalist forces, including fighters of Lebanon's Shiite militia Hezbollah, and Islamist rebels, said the Syrian Observatory for Human Rights.

Syrian and Russian aircraft carried out at least 40 strikes, it said.