GENEVA – The United Nations announced a record appeal for victims of the Syrian conflict on Monday as part of the largest request it has ever made for global humanitarian emergency financing.

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.

Half the total, $6.5 billion, was needed for Syria, in what Amos said was the biggest appeal ever for a single crisis. The conflict in Syria, now heading toward a fourth year, has created the worst displacement crisis since Rwanda's genocide 20 years ago, said Antonio Guterres, the high commissioner for refugees, calling it "the most dangerous for global peace and security since the Second World War."

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.

More than half of Syria's population of 22 million is now in need of aid, according to U.N. estimates.

In this citizen journalism image, a Syrian man held the body of child killed after a government airstrike Sunday in Aleppo. The Britain-based Syrian Observatory for Human Rights said Monday dozens of children were among scores killed in airstrikes a day earlier.

Around 1.7 million Syrians fled the fighting to seek shelter in neighboring countries in 2013, bringing the number registered with the U.N. 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.

More than 9 million people inside the country are now in need of help, U.N. officials say, including more than 6 million driven from their homes by fighting, often forced to move many times and facing an increasingly tough battle to survive.

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

"These findings show that starvation is now threatening large parts of the Syrian population," wrote David Miliband, the group's chief executive. "With polio on the loose, and a subzero winter already here, the people of Syria now face months of more death and despair."

Although aid agencies continue to get relief supplies through to most governorates, Amos said, more than 2.5 million Syrians are living in areas where fighting prevents sufficient or consistent aid deliveries; a quarter of a million Syrians are trapped in areas under siege by warring factions and cut off from humanitarian aid.

The scale and cost of Syrian relief operations is imposing acute strain on the resources of relief agencies whose 2013 aid appeal was financed at only 60 percent.

"It's clear that the appeals that are being made cannot be met only by the traditional donors," Guterres told reporters, appealing to emerging economies and Arab countries to support the U.N. effort.

Amos said the $13 billion appeal is intended to help more than 50 million people in 17 countries, including the Central African Republic, victims of the typhoon in the Philippines and "persistent" crises areas Afghanistan and Haiti.