The number of people inside Syria in need of emergency humanitarian aid is expected to rise to more than four million early next year, while refugee numbers will soar to 700,000, the head of the UN's humanitarian efforts said Friday.
"In the early new year... we're predicting that the numbers of people in need will exceed four million, up from 2.5 million," John Ging, who heads the UN's Office for the Coordination of Humanitarian Affairs (OCHA), told reporters in Geneva.
"This will just continue to grow in the terms of humanitarian suffering."
Ging, who was speaking after a humanitarian forum on Syria, also said the number of refugees in neighbouring countries was likely to grow from more than 400,000 currently to around 700,000 -- a number already calculated into aid needs.
After various UN aid organisations presented their views on the situation to potential donor countries, Ging said the numbers he mentioned were "absolutely... not the worst case scenario."
"But it is an appalling scenario that should inspire and motivate" politicians and those in power to double their efforts to end the near 20-month conflict, he said.
"I don't want anybody to misunderstand (and think) that a large-scale, successful humanitarian operation is a substitute for conflict resolution.... It doesn't address the first demand of the people caught up in the conflict, which is protection and an end to the conflict."
The UN refugee agency said earlier that more than 11,000 Syrians had fled into neighbouring countries in the past 24 hours alone -- 9,000 of them flooding into Turkey.
The projected surge in refugee numbers would have "a phenomenally big impact on the region," and on the neighbouring "countries that are struggling at the moment to cope," Ging said.
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At the same time, he stressed that UN agencies and other aid organisations would not manage to scale up their efforts fast enough to meet the ever greater needs inside Syria.
"Since this (conflict) began, we have not been able to keep pace with the increasing need," he said, pointing out that UN humanitarian aid has reached around 1.5 million of the estimated 2.5 million people in urgent need despite the "Herculean effort" of the aid workers on the ground.
He explained that some 98,000 people were believed to be living in areas controlled by the opposition that aid organisations could not get to from inside Syria -- not because either side was refusing to allow them in but because it would mean crossing the deadly conflict line.
However, he added that there appeared to be other organisations bringing aid across the Turkish border to some of these areas.
This was something the United Nations could not do without explicit authorisation from the Syrian regime to cross its borders, which it has yet to give, Ging explained.
He said the main obstacle to rolling out the needed UN aid in Syria and to Syrian refugees was one of access due to lacking security and the dramatic underfunding of its efforts.
The United Nations has so far only received 45 percent of the money it has said it needs for aid efforts inside Syria until the end of the year, and only 35 percent of what it has appealed for to help the refugees in neighbouring countries, he said.
A number of countries present at Friday's humanitarian forum had pledged more money, including the United States which said it would give an additional $34 million, bringing its total humanitarian aid to Syria to $165 million.
The Syrian Observatory for Human Rights says more than 37,000 people have died since the uprising against Syrian President Bashar al-Assad erupted in March 2011, first as a protest movement and then an armed rebellion after the regime cracked down on demonstrations.