BEIRUT — The head of the main Syrian opposition group fighting to oust President Bashar al-Assad criticized U.S. officials Tuesday for saying it was premature to speak about a transitional Syrian government.

Abdelbaset Sieda told The Associated Press that the Syrian National Council is making "serious" preparations and consulting with other groups and rebels to form a government that could fill the leadership vacuum if Assad falls.

His comments came a day after French President Francoise Hollande called on the Syrian opposition to form a provisional government, saying France would recognize it.

But Hollande's statement, believed to be the first of its kind, was quickly shot down by U.S. officials who said it was premature to speak about a provisional government when Syria's fractured opposition hasn't even agreed yet on a transition plan.

Sieda admitted no names have been discussed and an announcement was not imminent but insisted various factions would eventually pull together.

Syria's opposition has been plagued by divisions and infighting since the start of the uprising last year, and forming a transitional government is fraught with difficulties.

In addition to the SNC, several other groups are known to be making similar plans, including a new alliance headed by veteran opposition figure Haitham Maleh.

The U.S. officials — speaking on condition of anonymity because they weren't authorized to speak publicly on the matter — cited persistent disagreements among factions including the Syrian National Council, rival groups, opposition figures campaigning outside the country, and rebels fighting the regime on the front line.

"We're nowhere near that yet," one U.S. official said.

Sieda said the U.S. comments show the international community is "not ready" to be decisive when it comes to Syria and is trying to put all blame on the opposition.

"Yes there are differences within the Syrian opposition and this is normal in any country, but as long as we are agreed on a common vision, these differences can be overcome," Sieda said in a telephone interview. "The international community must make a move before it's too late."

A series of international diplomatic efforts have failed to stop the bloodshed as the civil war intensifies. Human rights groups say more than 20,000 people have been killed in Syria since the revolt against Assad began in March 2011.

Syrian military helicopters dropped thousands of leaflets over Damascus and its suburbs, urging rebels to hand over their weapons or face "inevitable death."

The psychological warfare is part of a widening and deadly offensive to recapture areas near the capital that have fallen into rebel hands.

Across the country, fighting raged between rebels and government forces including in Aleppo and the southern province of Daraa and eastern and northern provinces of Deir el-Zour and Idlib.

In the town of Kfar Nabl in Idlib, activists said an airstrike killed at least 13 people Tuesday. Videos posted by activists online showed burning buildings, smoke and rubble that they said was the aftermath of an aerial attack.

In the Damascus suburb of Jaramana, a booby-trapped car exploded, killing a number of civilians, according to Syria's state-run news agency. SANA said the blast targeted a funeral procession for two people who were killed a day earlier in the area. It was the third bombing in Jaramana in the past 24 hours, according to SANA.

No further details were immediately available. The British-based Syrian Observatory for Human Rights said a bomb exploded during the funeral of two pro-regime civilians killed in overnight bombings in Jaramana.

For more than a month, the military has been fighting major battles against rebels in the outskirts of Damascus and its suburbs while engaged in what appears to be a stalemated fight in the north against rebels for control of Aleppo, the nation's largest city and commercial capital.

The government recently has stepped up its offensive to recapture rebellious districts on the capital's periphery, and hundreds of people have been killed in several days of shelling and clashes in the affected areas.

Over the weekend evidence mounted of mass killings by regime forces in the Damascus suburb of Daraya after it was stormed by troops.

Some of the leaflets dropped Tuesday, which were signed by the armed forces and the army's general command, read: "The Syrian army is determined to cleanse every inch in Syria and you have only two choices: Abandon your weapons . . . or face inevitable death."

"No one will help you. They have implicated you in taking up arms against your compatriots," they said. "They drown in their pleasures while you face death. Why? And for whom?"

Syrian authorities blame the more than 17-month uprising on a foreign conspiracy and accuse oil-rich Gulf countries Saudi Arabia and Qatar, in addition to the United States and Turkey, of backing "terrorists" seeking to oust the regime.

Assad told an Iranian delegation this week that he was determined to crush the conspiracy against Syria "whatever the price."

With its forces stretched thin by fighting on multiple fronts, Assad's regime has increasingly turned to air power, unleashing both helicopters and fighter jets on the rebels.

The lightly armed fighters, in turn, have grown bolder and their tactics more sophisticated in recent months. Rebels claimed to have shot down a military helicopter that crashed in flames in the Damascus district of al-Qaboun Monday. State media confirmed the crash but gave no details about the cause.