United Nations, Sep 18 (IANS): UN Secretary-General Ban Ki-moon has called for global efforts to make up for the huge shortfall in funding for the humanitarian crisis in Syria.

Addressing the 68th session of the UN General Assembly Tuesday, he warned thousands of Syrian refugees in Lebanon could face reductions in vital food aid, reports Xinhua.

"We have raised just 40 percent of the $4.4 billion needed for Syria and neighbouring countries for this year," Ban said at the session.

He called on governments to help meet this "unprecedented crisis" while still meeting their commitments to other emergencies.

The number of Syrian refugees has reached two million and the figure is expected to rise to 3.5 million at the end of this year, the UN refugee agency UNHCR said.

More than 100,000 Syrians have been reportedly killed, over two million have fled to neighbouring countries, such as Lebanon, Jordan and Turkey since the beginning of the political crisis and conflict in the Middle East country in March 2011.

Ban called the situation "desperate" in his briefing largely devoted to the findings of a UN report that Sarin gas was used in a chemical attack that reportedly killed hundreds of people on the outskirts of Damascus, the Syrian capital, Aug 21.

Outlining the severe consequences of the funding shortfall, UN agencies called for greater generosity to avert a cutback in food aid next month for thousands of Syrian refugees in Lebanon, where $127 million still needs to be raised.

Nearly 720,000 Syrians have so far poured into Lebanon, while funding for Lebanon is only 27 percent covered, UN High Commissioner for Refugees (UNHCR) spokesperson Melissa Fleming told a news briefing in Geneva, citing the needs of the UN World Food Program.