The United Nations has announced its biggest ever appeal, seeking $US6.5 billion for humanitarian aid to Syria.
Launching the appeal, UN High Commissioner for Refugees Antonio Guterres said the Syrian conflict was the most dangerous crisis for global security since World War II.
The UN estimates nearly three-quarters of Syria's 22.4 million population will need humanitarian aid in 2014, the BBC reports.
The appeal coincides with a new study by the International Rescue Committee, which warns that starvation is now threatening the Syrian population.
The group says bread prices have risen by 500% in some areas and four out of five of the Syrians surveyed said their greatest worry was that food would run out.
In total, the UN is asking for almost $US13 billion to fund its humanitarian operations next year, says the BBC.
Some $US2.3 billion is destined for civilians inside Syria, while $US4.2 billion would go to Syrian refugees in neighbouring countries.
The latest call exceeds the UN's record appeal for $US4.4 billion in June, of which only 60% has been funded so far.
"We're facing a terrifying situation here where, by the end of 2014, substantially more of the population of Syria could be displaced or in need of humanitarian help than not," said Mr Guterres.
He said the world should stand in solidarity with Syria's neighbours who were dealing with many of the refugees.
The UN estimates that millions of people have been displaced since the conflict broke out in March 2011.