The United Nations' food agency has announced that it is suspending its food programme serving more than 1.7 million Syrian refugees because it has run out of money.

The World Food Programme (WFP) said on Monday that it "immediately needs" at least $64m in December alone to support the displaced Syrians now living in neighbouring countries such as Jordan, Lebanon, Iraq and Turkey.

"A suspension of WFP food assistance will endanger the health and safety of these refugees and will potentially cause further tensions, instability and insecurity in the neighboring host countries," said WFP Executive Director Ertharin Cousin, in an appeal to donors.

"The suspension of WFP food assistance will be disastrous for many already suffering families."

Since the war in Syria began in 2011, over three million people have fled to neighboring countries.

Under the UN programme, the refugees use vouchers to buy food in local shops. The UN provides basics like flour, cooking oil and sugar. But it also gives vital food vouchers to pregnant and nursing mothers.

"Without WFP vouchers, many families will go hungry. For refugees already struggling to survive the harsh winter, the consequences of halting this assistance will be devastating," the UN said.

Every month, the UN feeds over four million people inside Syria, and over a million more now temporarily sheltered in other countries.

Harsh winter

Muhannad Hadi, the UN coordinator of the food programme, told Al Jazeera the refugees would face a harsh winter without support from the world body.

"It's definitely a catastrophe," he said, speaking from the Jordanian capital Amman. "If we cannot deliver the food voucher, they simply would not be able to eat."

"We are asking the world [to help]. This is an international crisis."

The UN refugee agency UNHCR said that a lack of cash had forced it to priorities as it helps those in need prepare for winter, with preference for people at higher, colder altitudes and vulnerable refugees such as newborn babies.

PHOTO CAPTION

Kurdish refugee children from the Syrian town of Kobani are seen in a refugee camp in the Turkish border town of Suruc, Sanliurfa province November 21, 2014.

Al Jazeera