The WFP said on Monday that a funding gap means it is no longer able to provide the vouchers. The total number of Syrian refugees currently registered with the United Nations stands at over 3 million.
The World Food Programme admitted yesterday that many families are likely to go hungry this winter, and said that the result of stopping the food voucher programme will be devastating.
It's not clear how the 1.1 million Syrians in Lebanon will find food without the programme's support.
But the United Nations said that it simply doesn't have the funds to continue providing the vouchers, explaining that it needs 51 million euros to support the refugees just until the end of December.
The programme, which works through electronic vouchers, had already provided 642 million euros to shops across the Middle East.
The UN says the programme will resume immediately if funds to support it arrive.
This will be the fourth winter that many Syrian families have spent out in the cold since the start of the uprising against President Bashar al-Assad in March 2011.
In Lebanon, a country without official refugee camps, many are forced to live out in the open in makeshift shelters.
The UN refugee agency, UNHCR, says it is now trying to direct funding to the neediest among the refugees, including those living in mountainous regions and young children.
The UN warned that their programme, which provides aid to the 7.6 million internally displaced people inside Syria, is also at risk, saying that funding shortfalls mean this programme could suffer a similar fate in January 2015.