Syria faces the risk of mass starvation or another mass exodus, unless more money is made available, said the head of the UN World Food Program.
Before a donor conference in Brussels on Tuesday, David Beasley told the BBC that one million Syrians were seriously insecure about food and some were already dying.
The currency of the war-torn country collapsed and food prices rose.
In desperation, many Syrians may have no choice but to try to escape to Europe as they did in 2015, Beasley said.
More than 380,000 people have been killed and 13.2 million others – half the population before the war – have been displaced in and out of Syria since an uprising against President Bashar al-Assad began in 2011.
About 6.6 million refugees are spread across the world, the vast majority of them in Turkey, Lebanon, Jordan, Iraq and Egypt, where the impact of the Covid-19 pandemic has wreaked havoc on economies.
“The whole world is facing a crisis unlike anything we have seen in everyone’s life. But frankly, what is happening in Syria is unprecedented. It is the worst of all storms that happen,” said Beasley in an interview.
WFP’s executive director said immediate measures are needed to prevent further suffering and death among Syrians, 11 million of whom need help and protection.
“We have to have the money and we need to have access. And I don’t mean that we need to speculate a year from now – we need it now. We have people on the verge of starvation now, and they can’t wait. People are going to die and people are dying while we talk. “
In describing Syria as “a political quagmire,” Beasley urged Western countries to overcome their weariness with the long-running war.
He said world powers must allow aid to reach areas controlled by the opposition in Syria, as well as those controlled by the government.
Beasley’s message to donors ahead of Tuesday’s conference was that desperate Syrians might have no choice but to try to flee to Europe again.
“If we don’t have the money, here’s the main point: you will have mass migration, famine or exploitation by extremist groups,” he warned. “I think people are leaving, just like they did five or six years ago.”
While hostilities in Syria have generally subsided, there are tensions and outbreaks of violence in the northwest, northeast and south, including the resurgence of jihadist groups affiliated with Islamic State.
The UN and its partners have asked for $ 3.8 billion (£ 3.08 billion) for humanitarian work in Syria and another $ 6.04 billion to help countries in the region that receive Syrian refugees. Currently, resources are 30% and 19%, respectively.
The United Nations High Commissioner for Refugees, Filippo Grandi, warned that the Covid-19 crisis had an immediate and devastating impact on the livelihoods of millions of Syrian refugees and their host countries, where there were severe economic crises and poverty increased.
“The most vulnerable in society – including millions of refugees – have lost their already fragile and meager income. They are sinking further into poverty and debt,” he said in a statement.
“The international community must join in the sustained and predictable support for Syrian refugees and the countries and communities in the region that have received them generously for years.”