The United States on Thursday denied it used its overseas aid agency to mount a covert operation on social media to incite unrest against Cuba's communist leaders.
But the US Agency for International Development (USAID) did say it had created a Twitter-style application on which Cubans, subject to strict curbs on expression, were able to "talk freely among themselves" consistent with universal rights and freedoms.
White House spokesman Jay Carney said that the program was a "development assistance" scheme designed to allow Cubans facing government restrictions on information access to civil society and was not a secret.
He said the program, first reported by the Associated Press, was conducted within US law, and had not been a secret since it was debated in Congress.
"When you have a program like that in a non permissive environment, i.e. a place like Cuba, you are discreet (in) how you implement it so you protect the practitioners," he said.
"But that does not make it covert. USAID is a development agency, not an intelligence agency. Suggestions that this was a covert program are wrong."
USAID spokesman Matt Herrick said in a statement that USAID was proud to work in Cuba to "promote human rights and universal freedoms" and to help information flow to its people, alongside its humanitarian operations.
The project was known as "Zunzueneo" after the term for a Cuban hummingbird and was a platform for Cubans to "speak freely among themselves," said Herrick.
He said the application was built to build interest and engage Cubans using sports scores, weather, and trivia.
Questions were raised about the program after the initial AP report suggested that political content was to be introduced at a later stage to encourage Cubans to mount "flash mobs" and demonstrate against the communist government.
Despite the US denials, fears are likely to be expressed that the use of USAID in the program could politicize an agency which often relies on the goodwill of foreign governments to carry out humanitarian work.
Patrick Leahy, chairman of the Senate Judiciary Committee said he had not been briefed on the program, which he called "dumb, dumb, dumb."
"If you are going to do a covert program like this for regime change, assuming it ever makes any sense, it's not something that should be done through USAID."
"They do a lot of great things around the world ... this is not one of them," Leahy told MSNBC.
The agency says openly on its website that its core mission in Cuba includes promoting the freedom of expression.
It says its program provides basic news and information about issues relevant to Cubans from "inside Cuba and around the world."
It uses books, magazines, newspapers, and pamphlets "with an increasing emphasis on promoting the use of social media."
Carney said that Congress had appropriated funds to promote democracy in Cuba in an open fashion and that the program had been vetted by the Government Accountability Office, a federal watchdog body.
The confrontation between the United States and Cuba is one of the world's last Cold War-era disputes and Washington has maintained an embargo on the communist country since 1962.