The conflict in Syria has cost Lebanon $7.5 billion as it struggles to cope with hosting more than a million refugees from the neighbouring country, according to World Bank chief Jim Yong Kim.
"We estimated last summer that the impact of the crisis on Lebanon was $7.5 billion," Kim said late on Sunday in the Saudi city of Jeddah, which he visited in the first stop of a regional tour.
He said the conflict has had a "profound" impact on Lebanon and Jordan, which also hosts around 600,000 Syrian refugees.
The conflict that broke out in March 2011 with demonstrations against the regime of President Bashar al-Assad descended into a civil war that has killed more than 160,000 people, and driven millions from their homes.
Kim said the World Bank is trying "as much as possible" to help the two countries that host the largest Syrian refugee populations.
Lebanon's gross domestic product dropped 2.9 percent annually between 2012 and 2014, according to World Bank estimates, while 170,000 Lebanese fell into poverty and the unemployment rate doubled to more than 20 percent.
The World Bank warned that refugees in Lebanon and Jordan are putting extra strain on services such as water, electricity, waste disposal, primary education and health, while increasing competition for scarce jobs.
"The international community needs to step up its support to the Jordanian and Lebanese hosting communities," said Kim in the statement. "The people of these countries have demonstrated unprecedented generosity. They should not be left to shoulder this crisis alone."
After visiting Saudi Arabia, Kim will travel to Lebanon and Jordan.