Cuba's top envoy to Washington said yesterday that despite growing U.S. protests over the presence of more than 20,000 Cuban troops in Africa, nothing the United States can say or do will alter the Cuban committment there.

Ramon Sanchez-Parodi, head of the 10-man Cuban diplomatic interests section here, said in an interview that Cuba will not trade its ties with Africa for better relations with the United States.

Since the withdrawal of Cuban troops from Africa is the price the United States has set for further progress on normalizing the relationship between the two countries, it is unlikely that normaliztion is possible anytime in the near future.

The Cuban troop question has taken on virtually the same level of significance fo the United States that the U.S. trade embargo has long had for Cuba.

The Cubans have long maintained that there can be no substantive discussions on any issue inlcluding $4 billion worth of compensation for nationalized businesses in Cuba, until the U.S. embargo on trade with the island is lifted. The U.S. began to impose the embargo in October 1960

Now, a State Department official said yesterday, the United States feels that "there can be no sinificant progress, no new initiatives" until the number of Cuban troops Africa goes down.

The difference between the two positions is that, while the United States has consitently used the possible lifting of the embargo as its ultimate bargaining tool with Cuba, Havana has never given the slightest indication it is even willing to talk about Africa.

Cubans in Africa are nothing new, said Sanches-Parodi. Cuban troops fought with liberation movements in Guinea-Bissau, Algeria and Mozambique, he said. There are still an estimated 19,000 Cuban troops in Angola, and the United States recently estimated that more than 3,000 Cubans are in Ethiopia with the majority fighting in that country's war against Somalia.

Cuban assistance to "liberation organizations and newly-formed countries" has been "a consistent foreign policy in 1959," he said. "We have never hidden it or denied it."

Noting that Cuba is a "small country that has been forced to create a large defense capacity" because of years of "aggression and hostility," Sanchez-Parodi said that Cuban armed forces are "very efficient."

Cuban actions abroad, he said, have been taken exclusively "through agreements to defend (national) integrity. There has never been a Cuban soldier engages in invading" another country, he said. "Just defending."

Additionally, Sanchez-Parodi said, "we have proved for many years that we can help a country defend its sovereignty without any other aims. There has never been wa single Cuban enterprise remaining . . . not a single (Cuban) base" has remained in a country where Cuban troops have fought.

The comparison is indirectly made with the United Staes, which still maintains troops in Western Europe and many other parts of the world where the wars that put them there have long passed into history.

The Cuban presence in Angola, however, two years after Cuban troops swung the power balance in a civil war, is estimated at 19,000 military personnel and 4,000 doctors, teachers and technicians who show no sign of imminent departure.

The Cuban government does not often comment on those still-high levels. It is clear, however, that Cuba either wants to maintain a strong and readily accessible military reservoir on the African continent, or believes it is still necessary to prop up the Marxist government of Angolan President Agostinho Neto against continued guerrillo attacks.

In Ethiopia, where Cuba, along with the Soviet Union, is aiding the government in a war against neighboring Somalia, he said, "we subordinate ourselves" to the Ethiopians. "We are not acting as an expeditionary force, but as advisers, technicians and troops."

Somali forces now occupy an Oregon-sized piece of southern Ethiopia, and Cuba says it is helping the Ethiopians to reclaim the territory

"We are doing what Ethiopia asked us to do," Sanchez-Parodi said "Helping them to defend themselves against Somali agression.

In terms of payback, assistance to Angola and Ethiopia seems to be far more important to Cuba than the possibility of greater trade with the United States. While small concessions on prisoner releases, tourism and maritime limits with the United States may have been achieved over a relatively short period of time, few observers on either side think the trade embargo is close to being lifted, with or without Africa.

On the other hand, there is a promise relatively quick ideological and political return in the African venture.

After years of Cuban failure in Latin American countries that eventually turned more to the right than to the left, Cuba has found a different kind of battleground in Africa. The Marxist movements it supports are either defending a government they already control, as in Ethiopia, or had a good chance of winning civil wars at the time of Cuban entry, as in Angola.

For many Cubans, President Fidel Castro included, the ability to spare doctors, technicians and troops to send abroad is perhaps the clearest sign that the revolution has succeeded at home.

Regardless of Cuba's idelogical motivation in Africa, however, the bottom line is intagible credits gained by supporting the Africa policy of the Soviet Union, to which Cuba is indebted - in loans and price subsideies for Cuban exports and imports - to the tune of an estimated $3 million a day.