The Arab League has called on the various Syrian opposition factions to unite in light of their rejection of a U.N.-brokered plan for a transitional government that, as a gesture to Russia, would possibly include President Bashar al Assad in any decision-making on the country's future government.

Arab League Secretary General Nabil Elaraby told a gathering of 250 members of Syria's various opposition groups in Cairo on Monday they should form a united political front against the Syrian interim government.  

The sacrifices of the Syrian people are bigger than us and more valuable than any narrow differences or factional disputes, Elaraby told the representatives of opposition groups, including the Syrian National Council, according to the Associated Press.

U.N. special envoy Kofi Annan has lauded a plan to form a transitional government to end the country's civil war. The plan was approved Saturday in Geneva by an international delegation but was promptly rejected by Syrian opposition groups and the Arab League for two reasons: It offers no specific timeline for a definitive transition, and it does not explicitly exclude Assad from any transitional government.

We cannot say that there is any positive outcome today, Syrian National Council representative Bassma Kodmani told United Press International on Sunday. If we don't have firmness and clarity, we have more victims.

Annan's original proposal heading into the summit in Geneva was to exclude anyone whose presence would undermine the transition, meaning specifically the president of the country who has led a brutal crackdown on what his government calls a fight against terrorists.

Russia agrees with Assad, and in order to appease Moscow's recognition of the current Syrian government as the legitimate authority, the summit in Geneva ended by leaving open the possibility of Assad's continued participation in governing the country. Under the agreement, all parties must mutually agree to a transitional government.

The Assad government hailed the agreement as a victory, while the opposition dismissed the negotiations as time-wasting. Syrian opposition groups say they will never agree to negotiate a new government with the current one they blame for the bloodshed that has claimed at least 14,000 lives since the conflict began in the wake of Egypt's Arab Spring, which ousted President Hosni Mubarak.

Western powers are hoping the gesture to Russia will encourage it to put pressure on Assad to back off his crackdown on rebel forces, which are reportedly being armed by Arab Gulf states with the help of the U.S. and Turkey.

The Assad government forces are also reportedly being helped by Lebanese Hezbollah, which have long depended on material support from Iran, which, in turn, has for years received help from Syria in channeling arms to groups fighting Israel.