The volatility of global oil prices caused by the US and Israel’s war on Iran is taking a toll on the most vulnerable people, by slowing or blocking food and medical aid from reaching them.

Now aid organisations are calling for a “humanitarian corridor” to be opened through the strait of Hormuz amid rocketing transportation costs.

Bob Kitchen, vice president for emergencies at the International Rescue Committee (IRC) called for “serious and immediate conversations about humanitarian corridors through the strait of Hormuz so, at the very least, we can get supplies that are currently stuck in humanitarian hubs through the strait to resupply.”

Vital medicines are not making it out of key hubs. Shipping disruptions prevented the IRC accessing $130,000 (£96,000) of supplies stuck in Dubai that are needed by 20,000 people in Sudan. In Nigeria and Ethiopia, government oil rations meant the emergency relief body was having to limit generator use in its health clinics. “In certain parts of hospitals, we’ll have to close off the electricity to keep more important things running [if this continues],” said Kitchen.

He said aid agencies were burning through budgets rapidly. “It is more expensive to buy fuel to run our operations, moving commodities, moving personnel around many of the countries in sub-Saharan Africa,” he said.

Cecile Terraz, director at the International Federation of Red Cross and Red Crescent Societies, said: “The reality here is that it’s 100% sure that the increase of oil price is affecting the lives of people and also our operations.”

Since the conflict began in February, oil prices have fluctuated, peaking at almost $120 a barrel, up from $60 at the start of the year, as the US and Iran took turns at closing and blockading the strait of Hormuz shipping channel. Limiting the number of cargo ships passing through the 5km-wide passage has had an extraordinary global impact, reducing the global supply of oil, food, fertiliser and medicine, and driven up the price of what is available. The current cost of oil, a primary source of fuel, is nearly $111 a barrel.

Big aid agencies, still reeling from US and European funding cuts, have been badly caught out, because many export humanitarian products including food and medicines from hubs in India and Dubai to communities in need, many of which are in Africa.

Estimates by Save the Children found every $5 increase per barrel of oil cost the charity an additional $340,000 a month in shipping costs, fuel, food and medical supplies over what was budgeted for at the start of the year. That was equivalent to a month of aid for nearly 40,000 children, said the agency’s director of global supply, Willem Zuidema. If oil prices remained at about $100 for the rest of 2026, it would cost the charity an extra $27m this year, he said.

The disruption meant 45 million more people could go hungry, according to the World Food Programme (WFP), in addition to the 318 million people already considered food insecure before February’s attacks.

“We are being squeezed from both ends. While world leaders are cutting aid budgets, conflict is driving up the cost of every shipment, every sachet of food, every medical kit we send,” said Zuidema.

The US cut its foreign assistance by 57% in 2025, while UK aid last year was at its lowest since 2008. Norway, Germany and France have all slashed their aid budgets.

In Yemen, where, after more than a decade of war, nearly half the population is in need of aid, the cost of shipping in goods has risen by up to 20%, because of fuel costs, according to Save the Children’s estimates. Food prices there have risen by 30%.

In Somalia, Robyn Savage, Care’s humanitarian director, said the cost of importing key medications for acute malnutrition in children had tripled since the conflict began. “This means there is less medication available for those children, and that will result in fewer children being able to be treated,” she said.

The country, which is experiencing severe drought, has also seen the prices of basic foods rise by 20% as fuel prices drive up transportation costs, according to the World Food Programme (WFP).

In Myanmar, a basket of goods was up by 19%. And the cost of getting food into landlocked Afghanistan had tripled, said John Aylieff, the WFP’s Afghanistan country director.

The WFP’s supply of fortified biscuits was having to be transported by road through seven countries from Dubai to Afghanistan to avoid the usual route via the strait of Hormuz, said Aylieff, taking three weeks longer than usual. “Afghan children today are going hungry as a result,” Aylieff said, adding that many could die.

Another spokesperson at the WFP, the world’s largest humanitarian organisation, told the Guardian that the organisation had estimated the oil price increase meant it would not be able to reach approximately 1.5 million people around the world in the coming months. The UN agency is working to re-route about 93,000 tonnes of food, such as fortified biscuits and nutrition supplements, destined for communities with urgent needs, including refugees from the war in Sudan – the world’s largest humanitarian emergency – a significant cost and delay. It is not only ships routed through the strait of Hormuz being held up, they explained, but all shipping throughout the region was feeling the impact of the resulting widespread congestion at sea.

For example, supplies from manufacturing hubs in India typically sail from a port near Mumbai to Oman to Jeddah through the strait of Bab el-Mandeb and on to Port Sudan. Now due to risk and congestion, they sail around the Cape of Good Hope through the Mediterranean to the Suez canal and then on to Jeddah, adding 9,000km and several weeks on the journey.

In Bangladesh, the world’s largest development NGO, Brac, said its staff were spending five hours a week queueing for rationed fuel, reducing the amount of time they could spend working in refugee communities.

Even if a ceasefire held, Savage warned of ramifications for months to come. “We haven’t even seen the tip of the damage that’s already been incurred.”

In Sudan, Pakistan, Cambodia, Bangladesh and Ethiopia, where planting season has started, shortages of fertiliser and fuel will badly affect farmers’ ability to grow crops, driving up food insecurity, said Nick Jones-Bannister, of Mercy Corps. Up to 45% of the world’s seeds and fertilisers depend on access through the strait of Hormuz, according to the UN. “That will have a knock-on impact on civil conflict and on migration,” Jones-Bannister said.