Aid groups are warning that the war in the Middle East has upended their ability to get food and medicine to millions of people around the world in need, and that the suffering will deepen if the violence continues.

Not only has the conflict cut off vital shipping routes, creating a global energy crisis, it's also disrupting supply chains for aid groups, forcing them to use costlier, more time-consuming routes.

Key pathways such as the Strait of Hormuz have been effectively shuttered and routes from strategic hubs such as Dubai, Doha and Abu Dhabi have also been impacted. Transport costs have spiked with higher fuel and insurance rates, meaning less supplies can be delivered with the same amount of money.

The World Food Program says it has tens of thousands of metric tons of food heavily delayed in transit. The International Rescue Committee has USD 130,000 worth of pharmaceuticals intended for war-torn Sudan stranded in Dubai and nearly 670 boxes of therapeutic food meant for severely malnourished children in Somalia stuck in India. The UN Population Fund says it's delayed sending equipment to 16 countries.

Steep US cuts to foreign aid already had hobbled many aid groups, who say the war is exacerbating the problem.

The United Nations says this is the most significant supply chain disruption since COVID, with up to a 20 per cent cost increase on shipments and delays as goods are rerouted. And the Middle East war is creating new emergencies, such as in Iran, and also in Lebanon where at least one million people have been displaced.

"The war on Iran and disruption to the Strait of Hormuz risk pushing humanitarian operations beyond their limits," said Madiha Raza, associate director for public affairs and communications for Africa for the International Rescue Committee.

Even when the fighting stops, the shock to global supply chains could continue to delay lifesaving aid for months, she said.

Longer and more costly routes

The war has forced organisations to find new ways to transport goods, with some bypassing the Strait of Hormuz and the Suez Canal and rerouting vessels around Africa, adding weeks to the delivery.

Others are using a hybrid of methods, including land, sea and air, increasing costs.

Jean-Cedric Meeus, chief of global transport and logistics for UNICEF, said his agency is using a mix of land and air routes to send vaccines to Nigeria and Iran in order to get them there in time for the vaccination campaigns, but the costs have soared.

Before the war, UNICEF sent vaccines to Iran by plane directly from vendors around the world. Now it's flying the vaccines to Turkey and driving them into Iran, which has increased costs by 20 per cent and has added 10 days to the delivery time, he said.

Save the Children International, which would normally send supplies by ocean freight from Dubai to Port Sudan, will now have to truck the goods from Dubai through Saudi Arabia and then by barge across the Red Sea, it said. The route adds 10 days and increases costs by about 25 per cent, at a time when over 19 million Sudanese face acute food insecurity. The delay puts more than 90 primary health care facilities across Sudan at risk of running out of essential medicines, it said.

The spike in prices also means organisations have to choose what to prioritize.

"In the end, you sacrifice either the number of children that you serve ... or you sacrifice the number of items that you can afford to buy," said Janti Soeripto, president of Save the Children for the United States. The group said it has stockpiles in countries where it works but some of those could run out within weeks.

Rising costs are also impacting people's ability to seek help within their countries.

Doctors Without Borders said rising fuel prices across Somalia - where some 6.5 million people are experiencing acute food insecurity - have driven up transport and food costs, making it harder for people to get care. In Nigeria, the IRC says fuel prices have surged by 50 per cent and clinics are struggling to power equipment, such as generators and mobile health teams have scaled back operations.

Hunger crisis could deepen

One of the biggest concerns is the impact the war will have on global hunger.

WFP warns that if the conflict continues through June, 45 million more people will be acutely hungry, adding to nearly 320 million people facing hunger around the world.

Some 30 per cent of the world's fertilizer comes through the Strait of Hormuz and with planting season ahead in areas like East Africa and South Asia, small farmers in poor countries will be hard hit. Sudan imports more than half its fertilizer from the Gulf and Kenya approximately 40 per cent from there, aid groups say.

The UN secretary-general has established a task force to facilitate fertilizer trade - modeled on the Black Sea Grain Initiative. But aid groups say that won't be enough. If there's no ceasefire, governments need to provide more funding for organisations to respond to the rising costs, they say.

Humanitarian experts say there's been a slower international response to fund aid during this war compared to previous conflicts like Ukraine, which could reflect growing pressure to invest in security over aid at a time when the world is in turmoil.

"They're making hard choices between defense security and humanitarian aid," said Sam Vigersky, an international affairs fellow at the Council on Foreign Relations who has written about the war's impact on aid.

He said when the US goes to war, it normally has provisions for aid, but hasn't been "activating" those provisions. "It's not a capacity issue, it's a policy decision," he said.

Tommy Pigott, principal deputy spokesperson for the US State Department, said that the US has been the "most generous country in the world" when it comes to humanitarian aid.

The department said it's releasing an additional USD 50 million in emergency assistance to Lebanon, including to the World Food Program and working closely with the United Nations and others to address the humanitarian needs.