The embargo as a whole "could be classified as an act of genocide," Foreign Minister Bruno Rodriguez said before the U.N. General Assembly voted 187-3 in October to condemn U.S. policy toward Cuba for the 18th year running.

A dramatic argument - but the facts behind it are fuzzy and tangled in the bureaucracies of two hostile countries.

U.S. law exempted medicine and health care supplies from the embargo in 1992. It also lifted the ban on agricultural exports in 2000 and is now Cuba's biggest supplier of food - $710 million worth last year.

The U.S. says it approved about $142 million in commercial and donated medical exports to the communist island in 2008. So why did less than 1 percent of it get here?

The answer lies somewhere in a war of words between the estranged countries and provides a cautionary lesson as the U.S. and Cuba take halting steps toward better ties: Reality often takes a back seat to rhetoric.

Cuba claims that despite the embargo exemption, the U.S. government imposes extra regulations on medical exports to discourage American companies from participating.

U.S. medical-export firms interviewed by the Associated Press agree the paperwork can be troublesome, but say they won't go on the record or give specific examples for fear of jeopardizing pending or future export applications. Others complained about both sides in private, but said they preferred not to do so for attribution given how touchy a subject U.S.-Cuba relations can be.

The U.S. Commerce Department says it takes only about 14 days to get a license to export medical supplies to Cuba - about twice as fast as for ordinary exports to other countries.

Another factor, according to two U.S. suppliers and a research group, is that China or other countries provide the goods more cheaply.

"It's not the embargo," said John Kavulich, a senior policy adviser at the New York-based U.S.-Cuba Economic Trade Council, which provides nonpartisan commercial and economic information about Cuba. "These are economic and political decisions not to buy."

In his U.N. speech, and later to reporters, Mr. Rodriguez, the Cuban foreign minister, singled out the case of Alexis Garcia Iribar, a 6-year-old born in the eastern province of Guantanamo with a congenital heart defect who underwent successful but unnecessary surgery in March.

Mr. Rodriguez gave no further details, but said he could have mentioned a dozen other cases in which children between the ages of 5 months and 13 years also went under the knife for want of technology made only in the United States.

Mr. Rodriguez named four U.S. companies he said were blocked by the embargo from selling catheters or other desperately needed supplies to Cuba.

Two of them, Massachusetts-based Boston Scientific and AGA Medical of Minnesota, declined to comment. The parent company of another firm he mentioned, Applied Biosystems, said it has "not sought to sell products to Cuba, and has not applied for a license from the Commerce Department to sell products to Cuba."

The fourth company, NuMed, Inc. of Hopkinton, N.Y., would only say: "We will make every effort to work with the U.S. government and the Cuban government in order to get our product into Cuba to help their children."

To export to Cuba, medical-supply companies need licenses from the Commerce Department and Treasury that also must be reviewed by the Defense and State departments.

Once a sale goes through, a third party must verify the goods' arrival in Cuba to ensure they are not re-exported, or used for military purposes or human rights violations. Restrictions also apply to other countries' medical products with more than 10 percent U.S. content.

If machinery breaks, Cuba often can't get spare parts, and American firms may be denied U.S. permission to send technicians to the island to make repairs.

"The letter of the law allows [the exports], but in practice, it limits Cuba's options," said Lorenzo Anasagasti, president of the Cuban Oncology Society.

Commerce Department spokesman Kevin Griffis said licenses were approved for about $142 million in health care items for Cuba in 2008. He said the licensing process was not onerous.

So why did medical goods worth only $1.2 million reach Cuba last year? Mr. Griffis wouldn't comment.

Cuba often waits for allies to donate what it needs, said the trade council's Mr. Kavulich. "They'd rather get things for free than pay for them."

He said he worked with U.S. companies that brought the first sample medical equipment to Cuba after the embargo was loosened in 1992 - but Fidel Castro's government bought nothing.

Sales are possible. Two years ago, Miller Exports of Key West, Fla., sold about 100 portable sonogram machines to Cuba, items totaling less than $1 million. To get around servicing problems, it included 10 extra units that could be raided for spare parts.

But company head James Beaver also cited the China factor. He said Miller Exports once had a deal in principle to sell Cuba MRI machines, but a Chinese firm offered a lower price at the last minute.

How much American medical technology Cuba really needs is also open for debate. The communist government says no patient dies for lack of medicine or equipment in its universal health care system.

Also, Cuba's Health Ministry sends buyers to the U.S. "to buy everything we need" and carry them back without permits, said Dr. Anasagasti, the Cuban oncologist.

The buyers "are blond, with blue eyes," he said, "and they even speak good English."