Half the total is needed for Syria, in what Amos said was the biggest appeal ever for a single crisis. The war, now heading toward a fourth year, has created the worst displacement crisis since Rwanda’s genocide 20 years ago, said António Guterres, the high commissioner for refugees, calling it “the most dangerous for global peace and security since the Second World War.”

Valerie Amos, the undersecretary general for humanitarian affairs and emergency relief coordinator, told a news conference in Geneva that aid agencies needed nearly $13 billion for humanitarian relief operations worldwide in 2014. “This is the largest amount we have ever had to request at the start of the year,” she said.

GENEVA — The United Nations announced Monday a record appeal for $6.5 billion to help victims of the Syrian war, as part of the largest request it has ever made for global humanitarian emergency financing.


Humanitarian aid is not the solution to the crisis in Syria, Amos said, but expectations of what may emerge from a peace conference expected to begin Jan. 22 were only “modest at this point in time.”

Senior officials from Russia, the United States, and the United Nations are to meet in Geneva this week to consolidate preparations for the peace talks. But Laurent Fabius, France’s foreign minister, sought to lower expectations last week, expressing pessimism about the outcome.

The violence in Syria, which activists say has claimed more than 120,000 lives, appears to be spiraling.

On Monday, Syrian antigovernment activist groups reported what appeared to be a major escalation of the military’s prolonged siege of Aleppo, with video and witness accounts of a helicopter gunship attack in which crews dropped explosive barrels filled with TNT and shrapnel on more than 13 rebel-held neighborhoods.

Reports by the Syrian Observatory for Human Rights and others said that between 76 and 118 civilians, including as many as 28 children, were killed in the air assault Sunday.


The scope of the destruction appeared to be enormous, based on video clips uploaded by the observatory and Syrian social media users that could not be immediately corroborated for their authenticity.

The observatory, a group based in Britain that monitors the Syrian war through a network of contacts on the ground, reported further air attacks Monday, both in Aleppo and near the southern border with Jordan. But the extent of casualties and damage was unclear.

More than half of Syria’s population of 22 million is now in need of aid, according to UN estimates, and with no letup in the ferocity of the conflict, relief agencies are forecasting a further sharp rise in humanitarian needs in 2014.

About 1.7 million Syrians fled the fighting to seek shelter in neighboring countries in 2013, bringing the number registered with the United Nations refugee agency to 2.3 million in 2013.

Although the number of new registrations has slowed, the total is expected to exceed 4 million by the end of 2014.

A survey released Monday by the International Rescue Committee, a refugee relief group, found the price of bread in many parts of Syria had risen 500 percent over two years and more than three-quarters of the communities surveyed rated food as their greatest need.