Cuba is eager to do business again with American oil companies, an official says, expressing hope that Havana's opening with Washington will clear the way for their return after 55 years.

"Let them come. We're waiting for them. We have all kinds of business for them," Maria Yodalis Hernandez, spokeswoman for the Del Centro Petroleum Drilling and Extraction Company, an affiliate of state-owned Cupet, said Tuesday.

It's a change in policy that harkens back to the beginnings of the Cold War-era conflict between the two countries.

In 1960, Cuba's revolutionary leaders expropriated US refineries on the island without compensation after they refused to process Russian oil, prompting Washington to retaliate with a trade embargo.

The US embargo, which was expanded in 1962 and remains in place even though diplomatic relations were restored this year, still prohibits US oil companies from doing business in Cuba.

Hernandez said the Cuban government is hoping that the rapprochement begun between US President Barack Obama and Cuban President Raul Castro will help the Cuban oil industry.

The loss of access to resources and state-of-the-art technology due to the embargo has greatly damaged the island's oil industry, she said.

Del Centro recovers just five percent of the oil reserves available to it, Hernandez said.

"We don't have the technology to recover it," she told foreign correspondents visiting Matanzas.

"We hope that now, with this new opening, we will be able to show them that Cuba has oil opportunities," she said.

"And they know it," she added. "They were here before 1959 and explored us completely."

Cuba produces some 25 million barrels of oil a year, which accounts for nearly half of what the country consumes.

It imports the rest from Venezuela at a discount.

Cuban crude is extra-heavy, however, and can only be used to generate electricity and to make lubricants and asphalt.

The government is banking on its exclusive economic zone in the Gulf of Mexico for its oil future, assigning 22 of 59 blocs to foreign oil companies under risk service contracts.

International experts say the area probably holds five to nine billion barrels, while the government estimates there are as many as 20 billion barrels in untapped reserves.