WFP emergency coordinator for Syria Muhannad Hadi said the aid group was able to provide food assistance to around 2 million Syrians in March. Despite those efforts, civil war in the country is forcing humanitarian workers to make tough decisions.
"It has become a struggle now to move food from one area to the other with our warehouses and trucks getting increasingly caught in the crossfire," he said in a statement. "We are sometime left with the difficult decision of calling off the dispatch of food to a place where we know there is dire need for it."
WFP said there have been more than 20 attacks on its delivery vehicles and warehouses in Syria since it started working in the country in December 2011.
The Syrian Observatory for Human Rights, an opposition group in London, said March, with more than 6,000 deaths, was the deadliest month since the Syrian civil war began in 2011.
The March toll surpassed August 2012 as the deadliest month, when civil war claimed more than 5,400 lives.
WFP said it needs about $19 million per month to keep humanitarian work going on Syria.