The United Nations has set a date for talks between the Syrian government and opposition, in an attempt to push through the first such meeting since the start of the country's 32-month-old war.
The UN secretary general, Ban Ki-moon, said on Monday that the conference, to be held in Geneva on January 22, was "a mission of hope" to end the civil war and agree a transitional government "with full executive powers".
However Laui Safi, a spokesman for the opposition Syrian National Coalition, said shortly after the announcement that the group would only attend if the Syrian regime met its preconditions: the release of prisoners and relief for besieged towns, and that the current president, Bashar al-Assad, has no part to play in the new transitional government.
The SNC has also said it would need the support of all rebel brigades on the ground, including al-Qaeda-affiliated groups, before it began peace talks.
Al Jazeera's diplomatic editor, James Bays, said that setting a date was no guarantee that talks would go ahead, and was announced more out of frustration than a clear plan.
"The UN has tried to coax the opposition to the table previously. When that didn't work, they have had to set a date to try to force them to the table. Delegations will probably attend, but will they represent those on the ground? Probably not"
The announcement was made after talks between the UN's peace envoy, Lakhdar Brahimi, met Russian and US diplomats on Monday in Geneva.
Al Jazeera's Zeina Khodr said that the Assad regime was itself emboldened, had the upper hand on the ground militarily, and felt strengthened by Iran, its main ally, returning to the international fold following the agreement to suspend its nuclear programme in return for easing of sanctions.
The US secretary of state, John Kerry, said in a statement: "We are well aware that the obstacles on the road to a political solution are many, and we will enter the Geneva conference on Syria with our eyes wide open."
The UN said the Geneva talks would be international, but it was not clear from Ban's statement whether Iran would be invited. He said he expected "all regional and international partners to demonstrate their meaningful support for constructive negotiations".
"We will go to Geneva with a mission of hope,'' Ban said in his statement. "The Geneva conference is the vehicle for a peaceful transition that fulfills the legitimate aspirations of all the Syrian people for freedom and dignity, and which guarantees safety and protection to all communities in Syria."
At a Monday news conference, Brahimi said the full list of attendees had yet to be finalised. There would be a meeting next month on the subject and he hoped delegations would be decided by the end of the year.
Asked if Iran and Saudi Arabia were invited, Brahimi said a full list of those involved had not been established but that they would certainly be among those who may attend.