U.N.: World Must End 'Unconscionable' Human Cost' of Syria War

World leaders must put aside disagreements to end the four-year war in Syria that has exacted an "unconscionable" human cost, top U.N. officials said on Friday.

"We need world leaders to put aside their differences and use their influence to bring about meaningful change in Syria," the heads of several United Nations agencies said in a joint statement.

"The future of a generation is at stake. The credibility of the international community is at stake," it said.

Syria's conflict has left more than 210,000 people dead and 11.4 million displaced since it began in March 2011 with peaceful anti-government protests, eventually escalating into a full-blown civil war after the regime brutally cracked down on the demonstrations.

More than 12.2 million people in the war-torn country need life-saving aid and 3.9 million of those displaced have become refugees in neighbouring countries and further afield.

Syria's conflict "continues to exact an unconscionable human cost. A crisis that the international community has failed to stop," said the heads of the U.N. agencies for humanitarian affairs, health, food aid, refugees, Palestinian refugees and for children.

Their comments echoed a statement from U.N. chief Ban Ki-moon Thursday warning that the Syrian people "feel increasingly abandoned by the world."

The suffering continues "under the eyes of the international community, still divided and incapable of taking collective action to stop the killing and destruction," he said.

- Frustration at unfolding tragedy - 

The Friday statement that the conflict has continued despite top UN officials expressing their "horror, our outrage, our frustration as we have watched this tragedy unfold." 

They stressed their commitment to continue helping those "caught in the middle of this war. People who are vulnerable. Besieged. With nowhere to go."

The situation is dire, said the statement, also signed by the U.N.'s top experts on children and armed conflict and sexual violence in conflict.

"Children and young people are subject to and surrounded by violence, despair and deprivation," it said.

"Women and girls, and men and boys in detention, are at particular risk of sexual violence," it added.

To end the suffering, world leaders need to step up, the officials said, urging them "to press the parties to end indiscriminate attacks on civilians."

The international community must help ensure the lifting of sieges, "where more than 212,000 people have been trapped without food for months (and) to enable delivery of vital surgical and other medical supplies," they said.

It also needs to exert pressure "to end the collective punishment of civilians by cutting off of water and power supplies, and to avoid the complete collapse of the education system," they added.

According to a report issued Thursday by 20 human rights groups, nearly 10 million people inside Syria do not have enough to eat, and more than 11 million are in urgent need of clean water.