Special U.N. envoy Kofi Annan acknowledged in an interview published Saturday that the international community's efforts to find a political solution to the escalating violence in Syria have failed.
Annan also said that more attention needed to be paid to the role of longtime Syrian ally Iran, and that countries supporting military actors in the conflict were making the situation worse.
"The evidence shows that we have not succeeded," he told the French daily Le Monde.
Annan, the special envoy for the United Nations and the Arab League, is the architect of the most prominent international plan to end the crisis in Syria, which activists say has killed more than 14,000 people since March, 2011.
His six-point plan was to begin with a cease-fire in mid-April between government forces and rebels seeking to topple the regime of President Bashar Assad. But the truce never took hold, and now the almost 300 U.N. observers sent to monitor the cease-fire are confined to their hotels because of the escalating violence.
Activists reported more than 50 people killed on Saturday alone, after some 800 people last week.
Annan defended the unarmed observers, saying it was not their job to stop the violence, but to monitor the sides' adherence to the truce.
He offered few suggestions on how the plan could be salvaged, only saying that Iran "should be part of the solution" and that criticism too often focused on Russia, which has stood by the regime.
"Very few things are said about other countries that send arms and money and weigh on the situation on the ground," he said, without naming any specific countries.
It is unclear what role Annan envisions for Iran, a longtime Syrian longtime ally that has stood by the regime throughout the uprising. Tehran's close ties could make it an interlocutor with the regime, though the U.S. has often refused to let the Islamic Republic attend conferences about the Syria crisis.
Russia provides the Assad regime with most of its weapons. No countries are known to be arming the rebels, though some Gulf Arab states have spoken positively of doing so. The U.S. and other Western nations have sent non-lethal aid, like communications equipment.
The Syrian uprising began in March, 2011, when people first took to the streets to call for political reforms. Since then, the government has waged a brutal crackdown, and many in the opposition have taken up arms, sidelining peaceful activists and changing the conflict into an armed insurgency.
Scores of independent rebel groups now operate in the country, regularly attacking regime bases and convoys.
Activists in Syria on Saturday reported fierce government offensives to try to retake rebellious areas outside of the northern city of Aleppo and near the capital Damascus, as well as government shelling across the country.
The Britain-based Syrian Observatory for Human Rights, which relies on an activist network inside Syria, called the bombardment of a number of villages in Aleppo province "the most violent" since the army launched a recent campaign to retake control of the area.
The group said that rebels in the area had killed many regime soldiers in recent months. Three rebels and three civilians were killed in the province Saturday, it said. Five government soldiers also were killed when rebels blew up their vehicle.
The Observatory said at least 35 rebels and civilians were killed nationwide, plus 19 government soldiers.
The activist claims could not be independently verified. The Syrian government rarely comments on its military operations and blames the uprising on foreign-backed gangs seeking to weaken the country.
The violence has raised fears that the unrest will spill over into Lebanon, which has extensive sectarian and political ties to its eastern neighbor.
On Saturday, shells fired from inside Syria killed two Lebanese civilians and wounded 10 others, security officials said, in the latest incident of violence spilling across the border.
One woman was killed when a shell hit her home in the Wadi Khalid area of northeast Lebanon, also wounding five others. Another shell hit the nearby village of al-Hisheh, killing an 8-year-old boy and wounding his father and four other children.
The officials spoke on condition of anonymity in line with government regulations.
Despite mounting international condemnation, Assad's regime has largely held together. On Saturday, however, France announced the defection of Brig. Gen. Manaf Tlass, an Assad confidant and son of a former defense minister who helped ease Assad into power.
Tlass is the highest ranking official to abandon the regime so far, and Western powers and anti-regime activists hoped his departure would encourage others to leave, too.
News of the defection largely overshadowed an international conference in Paris on Saturday attended by the U.S., its European and Arab partners and members of Syria's fractured opposition.
The so-called "Friends of Syria" said they would provide means for the opposition in Syria to better communicate among themselves and with the outside world and increase humanitarian aid.
They also called on the U.N. Security Council to adopt a resolution that would force the regime to comply with the two peace plans that have been largely ignored by both sides in the conflict.
Syrian allies Russia and China would likely veto any resolution seen as too critical of the Syrian government, as they have in the past.
About 100 demonstrators marched against Assad's regime in Paris on Saturday. Many were disappointed that the Paris conference had not led to more specific actions against the regime.
"Meeting just to talk is useless," said protester Hende Khattav, a Syrian who has lived in Paris for 37 years. "We have to do something. There has to be a useful action to make this massacre of the Syrian people stop."