WASHINGTON — Even as Americans debate whether to scrap President Obama’s healthcare law and its promise of guaranteed health coverage, many far less affluent nations are moving in the opposite direction — to provide medical insurance to all citizens.

China, after years of underfunding healthcare, is on track to complete a three-year, $124-billion initiative projected to cover more than 90% of the nation’s residents.

Mexico, which a decade ago covered less than half its population, just completed an eight-year drive for universal coverage that has dramatically expanded Mexicans’ access to life-saving treatments for diseases such as leukemia and breast cancer.

In Thailand, where the gross domestic product per person is a fifth of America’s, just 1% of the population lacks health insurance. And in sub-Saharan Africa, Rwanda and Ghana — two of the world’s poorest nations — are working to create networks of insurance plans to cover their citizens.

“This is truly a global movement,” said Dr. Julio Frenk, a former health minister in Mexico and dean of the Harvard School of Public Health. “As countries advance, they are realizing that creating universal healthcare systems is a necessity for long-term economic development.”

Many countries are still struggling to improve the quality of their medical care. And making healthcare affordable remains a challenge for most countries, as it does for the U.S., where about 15% of the population lacks coverage.

But the international drive to provide healthcare for everyone is increasingly leaving America behind.

“We are really an outlier,” said David De Ferranti, a former World Bank vice president who heads the Results for Development Institute, an international nonprofit based in Washington.

That stands in stark contrast to America’s historic leadership in education, he said. Long before most European countries, the United States ensured access to public schooling. Today, the U.S. is alone among the world’s richest nations in not providing healthcare coverage to all citizens.

Although the new U.S. health law is scheduled to do that in 2014, former Massachusetts Gov. Mitt Romney, the presumptive Republican presidential nominee, has promised to repeal it. Romney’s alternative does not include any provision to guarantee coverage.

Two decades ago, many former communist countries in Eastern Europe and elsewhere dismantled their universal healthcare systems amid a drive to set up free-market economies.

But popular demand for insurance protection has fueled an effort in nearly all of these countries to rebuild their systems. Similar pressure is coming from the citizens of fast-growing nations in Asia and Latin America, where rising living standards have raised expectations for better services.

Some countries have set up public systems like those in Great Britain or Canada. But many others are relying on a mix of government and commercial insurance, as in the U.S.

“People are demanding responses from their governments,” said Cristian Baeza, health director of the World Bank. Indeed, in countries such as India, politicians have learned that one of the surest ways to secure votes is to promise better access to healthcare.

In Chile, where free-market reforms eroded the country’s universal health system in the 1980s, a socialist candidate won the presidency in 2000 for the first time in nearly 30 years on a promise to renew guaranteed healthcare.

The Thai system, set up a decade ago, has survived years of political upheaval and a military coup. “No party dares touch it,” said Dr. Suwit Wibulpolprasert, a senior advisor to the Ministry of Public Health.

Many political leaders around the world also have concluded that creating a system of universal healthcare is crucial to remaining competitive globally and sustaining economic growth.

Chinese leaders were concerned their citizens were saving excessively because there was no system to protect them if they got seriously ill, said Yanzhong Huang, director of the Center for Global Health Studies at Seton Hall University. The high savings rate was restraining domestic demand for consumer items, making the economy overly dependent on selling goods abroad.

In Mexico, political leaders were alarmed to see that poor families were often forced to pull a child out of school or to give up productive assets such as livestock or equipment to pay medical bills, said Frenk, the former health minister.

Before embarking on its healthcare push, the Mexican government found that 4 million people every year were being driven into bankruptcy by illness. “That was a huge drag on the economy,” Frenk said.

Today, Mexico’s new government insurance plan — known as Seguro Popular — covers more than 50 million people, filling the gap left by the traditional health insurance system funded by payroll taxes.

Such steps don’t eliminate all financial strain on households. Indeed, in many poor nations that are expanding healthcare coverage, such as Vietnam and the Philippines, people still must pay most of their own medical bills, a sign of skimpy coverage.

Governments, too, feel the strain.Colombia’suniversal healthcare system, set up in 1993, has cost more than twice what was expected, said Ramiro Guerrero, a former vice minister of health.

Even so, there is growing evidence that universal coverage is protecting millions worldwide from financial ruin.

In Rwanda, researchers found that citizens who had joined one of the nation’s health plans were nearly 75% less likely to be hit with a catastrophic healthcare bill that threatened to bankrupt them.

And while the impact of broader coverage on overall health is still unclear, there are some signs that citizens of countries that are committed to guaranteeing health coverage are getting more treatment for serious illnesses.

In Mexico, the 30-month survival rate for children with cancer has more than doubled since the creation of the Seguro Popular program in 2003. In Ghana, visits to clinics and hospitals have doubled since the West African country passed a universal health law in 2003, said Nathaniel Otoo, general counsel for the National Health Insurance Authority of Ghana.

The universal system has also become a foundation for improving the quality of medical care in many countries such as China, where the government is now pushing a major overhaul in the way physicians are trained.

“That is the next challenge,” said Dr. Jeanette Vega, a former vice minister of health in Chile who is now managing director of the New York-based Rockefeller Foundation.

noam.levey@latimes.com