Syria announced last night it would stop fighting in time to meet this morning's deadline for a ceasefire brokered by Kofi Annan, the UN-Arab League special envoy. But it added a highly unpromising proviso.
Damascus said it reserved the right to respond to any attacks by "armed terrorist groups against civilians, government forces or public and private property".
Earlier yesterday, Mr Annan had expressed confidence he could salvage his faltering Syrian peace plan as he visited Iran on a regional tour to garner support to end 13 months of violence.
He said the Syrian government had assured him it would respect the ceasefire with rebel forces.
What they mean and want is an assurance that the other forces, the opposition forces, would also stop the fighting so there could be a cessation of all the violence," he said.
There was more bloodshed yesterday, with reports that regime forces had killed at least 11 civilians in bombardments on rebel areas.
Syria flouted a Tuesday deadline to withdraw its forces from urban areas.
Mr Annan had expected the Syrian regime, as the stronger party, to make the first move in a show of good faith, aware rebel forces were unlikely to budge before government forces pulled back, analysts said.
Mr Annan, meanwhile, warned that "any further militarisation of the conflict would be disastrous".
That was seemingly a message to Saudi Arabia and Qatar which have proposed arming rebels.
Western countries have also accused Iran, Syria's only regional ally, of helping President Bashar Al Assad quell protests by supplying his regime with crowd control equipment and technical assistance to monitor internet and cellphone communications.
It is unlikely, however, that Iran has sent arms to Syria, which seemingly has a plentiful supply from Russia, analysts said.
Mr Annan said it was important for regional governments help resolve the crisis.
His "constructive" Iranian hosts had agreed on the need to "find a peaceful solution", he added.
Privately, the former UN secretary-general will have appealed to Iran not to undermine international attempts to ratchet up the pressure on Mr Al Assad, analysts said.
Publicly, Tehran has voiced support for Mr Annan's peace plan, which calls for national dialogue but not, crucially from Iran's point of view, for Mr Al Assad to step down.
Iranian politicians have lavished praise on the Syrian dictator for his handling of the crisis, insisting he is committed to democratic reforms.
Tehran maintains western powers are stoking unrest in Syria to undermine Iran because it supports Mr Al Assad's "resistance" against Israel.
The Syrian regime has been the Islamic republic's staunchest Arab ally through three turbulent decades in the Middle East. Tehran's ability to project its power in the Arab world would be greatly reduced if Mr Al Assad is ousted.
Speaking alongside Mr Annan at a televised press conference in Tehran yesterday, Iran's foreign minister, Ali Akbar Salehi, said: "The opportunity must be given to the Syrian government to make changes under the leadership of Bashar Al Assad."
The Syrian people, he added, should be able to enjoy rights such as freedom of political parties and freedom of elections. But "at the same time we have announced that we oppose interference in the affairs of all nations, including Syria".
Iran would have been flattered by Mr Annan's visit, seeing it as acknowledgement of its role as an important regional power broker despite American attempts to isolate the Islamic republic.
Tehran resents being upstaged on the regional front by Turkey, Saudi Arabia and tiny Qatar.
In turn, however, Iran will be required to demonstrate that it can exert genuine pressure on Mr Al Assad to implement long-promised political reforms.
Whether Iran is willing to do so now without a significant reward is questionable.
"Syria is a playing card for the Iranians. Iran might only use it if there's a breakthrough in nuclear negotiations, which could mean an easing of sanctions against Tehran," Scott Lucas, an Iran expert at Birmingham University in England, said.
Iran and six leading world powers are due to open new nuclear talks in Istanbul on Saturday.
"You'd assume the Turks have more leverage over Iran than Annan, but they took their best shot last week and got nothing, absolutely nothing," Mr Lucas added in an interview.
He was referring to a visit to Tehran by the Turkish premier, Recep Tayyip Erdogan, who has repeatedly called on Mr Al Assad to step down and pressed Iran to end its support.
After months of expressing only outright support for Mr Al Assad, Tehran has recently shown signs of a more nuanced approach.
Iran's state-run Press TV referred yesterday to "the legitimate and peaceful demands of the Syrian people". Intriguingly, a senior Iranian politician said yesterday that Tehran has made contacts with the Syrian opposition aimed at reaching a peaceful settlement of the crisis.
Hossein Sheikholeslam, an adviser to Iran's parliamentary speaker, maintained this showed "Iran's influential role" as a regional peace-broker which had clout with both sides in the Syrian crisis.
But his revelation is unlikely to be welcomed by Damascus which might see it as a sign that Tehran is hedging its bets.
"As close as relations are between Iran and Syria, Ayatollah Khamenei [Iran's supreme leader] will not want to sink with Assad," said Meir Javedanfar, an Iranian-born analyst in Israel. "The moment he realises Assad's ship is sinking and unsalvageable, he will abandon him."