U.S. Energy Execs Discuss Cuban Oil Reserves

"The group will explore seven deep-water blocks estimated to contain more than 4 billion barrels in oil and gas reserves. Earlier explorations, however, turned up only modest discoveries.

"The petroleum reservoirs have fueled the Cuban government's hopes of increased self-sufficiency amid tightened U.S. sanctions.

"Since 2004, Cuba has pumped $1.7 billion into its energy sector with help from Canada, Europe and Latin America, Rivero Prieto said in a letter to the summit's organizers."

More: Will Cuban Oil Find Break U.S. Embargo?