The licenses were eventually granted and the government-employed doctors only recently received payments dating as far back as October, he said.
“The fact that they’re Cubans greatly limited the funds transfers and the payment,” Di Fabio said. “It’s not that the WHO didn’t want to pay, it’s that they weren’t able to.”
The US State Department had no immediate comment on Friday.
Cuban officials in Havana did not respond to requests seeking comment either.
US officials as high as Secretary of State John Kerry have praised the Cuban effort against Ebola.
But the longstanding embargo affects virtually all dealings with Cubans, even for banks outside the US, because theydepend on dollar transfers through US institutions.
Cuba has sent 256 medical workers to Africa, with 165 in Sierra Leone and the rest in Guinea and Liberia.
Cuban doctors generally receive salaries of about $70 a month, with some specialists earning more, but the Cubans in Africa are receiving $250 a day in direct payments from WHO that are meant to cover their food and lodging and provide a margin of extra compensation.
The embargo issue did not affect the state salaries, which are paid to banks inside Cuba, only the extra payments from WHO.
Di Fabio said there were relatively minor delays in opening accounts for the doctors in Guinea and Liberia, but those have been resolved.
There has also been a delay in deploying Cuban doctors in Sierra Leone, with only about 60 of 165 Cubans there in the field, said Dr Carlos Castro, leader of the Cuban doctors in Guinea.
Di Fabio said there was a clear need for “better coordination of efforts.”
He said that in Liberia, about 30 Cuban doctors are working closely and efficiently with US doctors in a centre built by the US Agency for International Development.