GENEVA: The UN refugee agency warned Thursday there could be as many as 700,000 Syrian refugees in countries neighbouring the war-torn nation by the end of the year, up from 300,000 now.

“There may be up to 700,000 Syrian refugees in neigbouring countries by the end of the year,” Panos Moumtzsis, the UNHCR's chief coordinator for Syrian refugees, told reporters in Geneva.

“We are running out of time,” he added.

Faced with the soaring need for aid, humanitarian agencies upped their call for funds Thursday to $487.9 million (379.2 million euros) to sustain their operations until the end of the year.

At present, only $141.5 million in funding is available, just 29 per cent of the overall request, Moumtzsis said, stressing the urgency of the appeal in the face of an “overwhelming increase” in the number of refugees fleeing the 18-month conflict.

In March, the UNHCR had registered 41,500 Syrian refugees and said it expected the number to rise to 100,000 by the end of this year, but that figure was surpassed in July.

The approach of winter made Thursday's appeal even more important, Moumtzsis said, adding that winterised tents, clothing, blankets and heaters were needed to prepare for the “very harsh” winter months.