International peace envoy Lakhdar Brahimi has warned 100,000 people could die in Syria in the next year unless world powers press the Syrian government and rebels to negotiate an end to their 21-month conflict.

Speaking Sunday in Cairo, Brahimi said the warring sides are not speaking to each other, despite his recent intensified diplomatic efforts to promote a peace plan approved by world and regional powers last June in Geneva. The U.N.-Arab League envoy said “help is needed from the outside” to start a Syrian national dialogue based on that plan.

The Algerian says the situation in Syria is deteriorating and if the civil war continues, Syria will turn into a Somalia-style failed state ruled by warlords.

The Geneva plan calls for all sides in Syria to end hostilities, enter a national dialogue, and form a transitional government leading to new elections. It says nothing about the fate of President Bashar al-Assad, an omission that appears to have stalled its progress.

Rebels refuse to negotiate unless Mr. Assad steps down and leaves the country, while the Syrian president insists on fighting what he calls “foreign-backed terrorists.”

Turkish Prime Minister Recep Tayyip Erdogan said Sunday he believes Syria's rebels will achieve victory soon with “God's help.” He was speaking to a cheering crowd of Syrian refugees at a Turkish camp near the border with Syria. The head of the exiled opposition Syrian National Coalition, Moaz Al-Khatib, accompanied Mr. Erdogan on the visit to the Akcakale camp.

Turkey is one of the strongest regional opponents of Mr. Assad and has provided shelter to about 150,000 Syrian refugees.

Russia, one of Mr. Assad's few remaining allies, appeared to be making more preparations to evacuate its citizens from Syria as the conflict escalates. In reports published Sunday, Russian media said Moscow is sending a third warship to its naval base in the Syrian port of Tartus, joining two vessels already en route. The news agencies said the third ship, the Novocherkassk, is expected to arrive at Tartus in early January.

Rights groups estimate at least 40,000 people have been killed in Syria since President Assad began violently cracking down on what started as peaceful pro-democracy protests in March 2011. The protests evolved into an armed rebellion aimed at ending the Assad family's four-decade authoritarian rule.