Head of the UN refugee agency warned on Thursday that the spiraling refugee crisis brought on by Syria's foreign-charged war could pose a serious threat to Lebanon's security and destabilize the entire region unless donors quickly provide the unfunded 70 percent of the $3.74 billion needed for emergency needs.

Antonio Guterres says that the upwardly revised assessment of needs is based on a new estimate there will be at least 3.6 million Syrian refugees by the end of the year.

He said in a statement that donors have contributed just $1.1 billion so far toward efforts in Lebanon, Jordan, Turkey, Iraq and Egypt, and failure to provide more "could result in dramatic consequences for refugees and the stability of the entire region, including a serious security threat to Lebanon."

The UN High Commissioner for Refugees (UNHCR) also warned of rising number of Syrian refugees in Jordan.

"We expect that the number of (Syrian) refugees will continue to increase to some 700,000-800,000 by the end of this year," said Andrew Harper, representative of the UNHCR in Jordan.

"There is a regional response plan and national response plan, in which many aspects are still being finalized... Basically $1 billion for the refugees and $1.6 billion for supporting Jordan's hosting community."

The UNHCR had so far received $400 million for the more than 600,000 Syrian refugees that Jordan is already hosting.

Syria sank into war in March 2011 when pro-reform protests turned into a massive insurgency following the intervention of Western and regional states.

The unrest, which took in terrorist groups from across Europe, the Middle East and North Africa, has transpired as one of the bloodiest conflicts in recent history.

SHI/SHI