For 5-year-old Manuela, the "magic word" is not please or thank you, it's "libertad"—the Spanish word for freedom. That's the term she's heard her mother say repeatedly in the 15 months since her father, Venezuelan opposition leader Leopoldo Lopez, has been in prison. "We are going to free daddy," Lilian Tintori told her daughter in Spanish during a roundtable at the Council on Foreign Relations on Wednesday. Tintori was in Washington to accept an award on her husband's behalf from the nonprofit National Endowment for Democracy. While here, she spoke about her husband's situation to members of the Council on Foreign Relations, an influential foreign policy organization.

Leopoldo Lopez is escorted by the National Guard after turning himself in, during a demonstration in Caracas on Feb. 18, 2014. Juan Barreto | AFP | Getty Images

Her Washington trip comes as the health of the Venezuelan economy continues to hit new lows. The country's black-market exchange rate fell below 300 bolivars per U.S. dollar on Thursday. In 2012, a dollar exchanged for 10 bolivars, and even as recently as April 2013, when current President Nicolas Maduro was inaugurated, a dollar brought 24 bolivars. Lopez, whose trial is underway, is accused of conspiracy and of inciting violent protests against the government. Last year, Lopez and other opposition leaders called for peaceful demonstrations against Maduro's government amid Venezuela's ongoing economic implosion. Read MoreThe oil rally's winners and losers

Venezuela's staggering inflation rate of 68.5 percent, its currency controls and lower oil revenue have generated scarcity of basic goods such as flour, toilet paper and medicine. Venezuelans stand in lines for hours outside supermarkets to buy whatever may be available.

Last year, a wave of violence after anti-government protests resulted in the deaths of dozens of protesters. That unrest marked the beginning of a political crisis Venezuela. "Soon [Lopez] will have to see a prison because of his crimes," Venezuelan President Nicolas Maduro said last year in a televised address to the nation. "That fascist fugitive has to go to jail."