Dr. Wahid Majrooh, left, Afghanistan’s health minister, toured a coronavirus ward in the Afghan Japan Communicable Disease Hospital, in Kabul, earlier this month.Credit...Victor J. Blue for The New York Times

The health care system in Afghanistan is teetering on the edge of collapse, endangering the lives of millions and compounding a deepening humanitarian crisis, public health experts warn.

The country’s health care has been propped up by aid from international donors. But after the Taliban seized power, the World Bank and other organizations froze $600 million in health care aid. The Biden administration, too, is struggling with how to dispense donor money to a country now being run by several senior Taliban leaders whom the United States has designated to be terrorists.

If World Bank funding is not restored quickly, an exodus of health care workers may result. Many have remained on the job despite significant personal risks; already some have not been paid for months. Along with the loss of supplies, the cutoff would effectively end health care services in 31 of the nation’s 34 provinces, humanitarian groups say.

Afghanistan is already on the brink of universal poverty, according to a United Nations report on Thursday, and only its richest citizens will be able to afford health care. Assuming that health care coverage is cut by half because of the funding loss, deaths among women and children will increase by at least 33 percent over the next year — nearly 2,000 women and more than 26,000 children per year — according to one analysis.

“There have been massive improvements in many metrics of health, like maternal mortality, tuberculosis and malaria,” said Peter Sands, executive director of the Global Fund, an advocacy group that funds campaigns against H.I.V., malaria and tuberculosis.

“There’s a real question as to how those are sustained, and what a tragedy it would be if that was reversed.”

In recent years, Afghanistan had made big strides in reducing maternal and child deaths by more than 50 percent, and increasing life expectancy for men and women by 10 years. Even so, most Afghans have had access to only rudimentary health care. The loss of humanitarian aid, and the looming fourth wave of the coronavirus, could devastate the nation.

“We are losing personnel, we are losing lives, and the morale and momentum we had,” said Dr. Wahid Majrooh, who was health minister under the previous government and has stayed on. “The crisis is very, very extensive.”

Afghanistan emerged from a third wave of virus infections just a few weeks ago, but it is already seeing a small uptick in cases, this time of the highly contagious Delta variant. Only 5 percent of the population have received at least one dose of a Covid-19 vaccine.

“It’s terrible timing that this would happen, when right now we’re faced with a situation where humanitarian needs are escalating,” said Dr. Richard Brennan, the regional emergency director for the World Health Organization’s Eastern Mediterranean region.

Cesarean sections, immunizations for polio, tuberculosis, tetanus and measles, diagnoses and treatment of TB, malaria, H.I.V., childhood nutrition, surgeries and routine health services, including family planning — all are at risk. The loss in aid is also constricting supply chains for medicines, oxygen and food for hospitals.

Roughly two-thirds of the country’s health facilities are part of Sehatmandi, a three-year, $600 million project administered by the World Bank and funded by the U.S. Agency for International Development, the European Union, the World Bank and others.

Because funds were put in effect through the Afghanistan Ministry of Public Health, the donors withdrew their support after the Taliban’s ouster of the previous administration.

Dr. Majrooh, who studied global health policy at the London School of Hygiene & Tropical Medicine, said he appreciated the precarious situation of donor organizations but argued that the health of the population should supersede political considerations.

Dr. Majrooh and humanitarian aid experts accused the funding organizations of abandoning Afghans when they most needed help.

“I’m so surprised that at the time where they are the most needed, and where they can have the highest impact ever — it is at that time they have decided to pull out,” said Karl Blanchet, an expert in humanitarian studies at the University of Geneva who has worked closely with the Afghan health ministry.

But others noted that the World Bank is hamstrung by limits set by its shareholders, and it had no choice but to withdraw financial support when similar upheavals unfolded in Yemen and Myanmar.

“They have rules and regulations that don’t allow them to contribute funding to a government run by the Taliban,” Dr. Brennan said. “So they’ve got to find an alternate funding mechanism to channel those funds to ensure those health facilities continue to operate.”

The shuttering of Sehatmandi clinics in Afghanistan is likely to overwhelm those funded by other means, aid workers said. In Herat, a hospital supported by Doctors Without Borders is among the few to remain open, according to Dr. Tankred Stoebe, the organization’s medical coordinator for the region.

The 40-bed health care center is treating nearly three times as many children as usual, many of whom had to travel for hours for treatment, he said, and staff members have not had a day off in weeks. “We are totally stretched at the moment,” Dr. Stoebe said.

One pediatric doctor at a Sehatmandi hospital has not been paid for three months, Dr. Stoebe said. The doctor already worked substantial overtime, but had tacked on more hours at a private clinic to make ends meet.

When no commercial flights were allowed into the country, medical supplies at many hospitals dwindled. Insurance costs for flights have skyrocketed, and funds don’t go as far. Trauma and emergency health kits, and testing kits for the coronavirus, are in particularly short supply.

The Sehatmandi program contracts out the delivery of health services to more than 30 nongovernmental organizations. On Aug. 31, a week after the funding pause, an alliance of some of the NGOs warned that absent of immediate solutions, the organizations could not continue their work after Sept. 5.

Without money for salaries or supplies, “we will be unable to offer our commitment for the continuation of services,” the organizations said in a letter to Dr. Majrooh. They urged the new regime to “take over all health facilities effective 10 September.”

Dr. Majrooh said that he had communicated the urgency and scale of the crisis to Taliban leaders, but that no plan had yet materialized for assuming control of the country’s health care system.

The NGOs also plan to appeal directly to the World Bank and other donors to resume support. But a sustainable solution may take time.

In the short term, the W.H.O. plans to spend $66 million to keep 538 health care facilities afloat through the end of the year, Dr. Brennan said. In the meantime, representatives from the World Bank and global health organizations are working closely to come up with alternative funding mechanisms, according to several people familiar with the discussions.

“We are deeply concerned about the situation in Afghanistan and the impact on the country’s development prospects, especially for women,” said David Theis, a spokesman for the World Bank. “We will continue to consult closely with the international community and development partners.”

Dr. Majrooh said he had sent several emails and messages to representatives of the major donors, asking to discuss options for funding Sehatmandi, but he had not received an official response.

“The ministry is left out of the communication chain, and somehow sidelined,” he said.

The donors could fund the NGOs directly, set up an independent organization to manage the money, or route the money through the W.H.O. and other arms of the United Nations. The W.H.O. already funds health programs in many countries.

Based on observations by its polio workers, the W.H.O. estimated last week that more than 90 percent of 2,200 health facilities for which they have information remained operational to some limited extent, and more than 90 percent of female health care workers — needed to to ensure that women can receive health services — were still showing up to work.

“While this data is encouraging for the moment, we are obviously worried,” Dr. Brennan said. “It would be irresponsible not to plan for this and not to raise the alert.”