Prime Minister Saad al-Hariri said Lebanon was close to "breaking point" due to the strains of hosting 1.5 million Syrian refugees, and he feared unrest could spiral from tensions between them and Lebanese communities.
Refugees who fled the six-year-long conflict in neighboring Syria make up a quarter of Lebanon's population, and most live in severe poverty in makeshift camps across the country as the government opposes the creation of formal ones.
"Today if you go around most of the host communities, there is a huge tension between the Lebanese and the Syrians... I fear civil unrest," Hariri told journalists working for foreign media on Friday.
He will urge the international community to boost financial support for Lebanon at a conference on Syria in Brussels next week. "I am going ... to make sure that the world understands that Lebanon is on the verge of a breaking point," he said.
Hariri said the country has been "extremely lucky in making sure this crisis has not affected host communities, but we have stretched our luck".
The Syria war has weakened Lebanon's economy, fuelled tension among Lebanese allied to the rival sides, and triggered a number of jihadist attacks. But there has so far been no significant violence between Syrian refugees and Lebanese host communities.
Hariri urged the international community to commit to spending the equivalent of $10-12,000 per refugee over a period of five to seven years, compared to the current level of foreign support equivalent to $1-1,200 per year.
"I think that will make sure that Lebanon is going to stand on its own and the economy will thrive," he said.
Georges Ghali, programs manager at Lebanese human rights organization ALEF, said the tensions were rooted in factors such as misperceptions held by Lebanese that refugees were being showered in aid, and government policies that had made it difficult for them to obtain official residency.
Tensions had not reached the point of violent escalation, Ghali added.
Lebanese officials, citing World Bank figures, say the cumulative cost of the Syrian conflict to Lebanon was $18.15 billion to the end of 2015. Lebanon's annual economic growth has slowed to just over 1 percent from an average of 8 percent before the Syrian war, officials have said.
The government is seeking financial support for a program of public sector-led investment in infrastructure to boost the economy, and to increase the number of Syrians in education.
Hariri, a Saudi-allied Sunni politician, became prime minister in December in a political deal that saw Michel Aoun, an ally of the Iranian-backed Shi'ite group Hezbollah, elected head of state.
Hezbollah, which is fighting in Syria in support of President Bashar al-Assad, is also part of the government.
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