Cuba on Wednesday accused the United States of unfairly denying its consular officials access to one of the members of the "Cuban Five" group convicted of espionage in the United States.
Cuban officials said in a statement that for several months they have been denied permission to meet with Rene Gonzalez, 56, who is on probation in the United States after serving a 13-year prison sentence for espionage.
"Since September of 2012, the Department of State has denied all requests by the Cuban Interests Section in Washington to let Cuban diplomatic officials visit Rene," the Foreign Ministry in Havana said in a statement.
Havana said the "deliberate and cruel decision also represents an additional punishment that is added to the already strict conditions of Rene's supervised release."
The foreign ministry statement also accused the United States of "toughening the conditions of his supervised release, making it seem even more as prison conditions, with the aim of continuing to punish him after so many years of unfair and cruel treatment."
Gonzalez was arrested in 1998 along with the other members of the Cuban Five -- Gerardo Hernandez, Ramon Labanino, Antonio Guerrero and Fernando Gonzalez.
The five men were found guilty in 2001 of trying to infiltrate US military installations in South Florida and were given long prison terms, ranging from 15 years to life. Gonzalez was released from prison in October 2011.
Cuba has acknowledged that the men were intelligence agents, but says they simply aimed to gather information on "terrorist" plots by Cuban expatriates in Florida -- not to spy on the US government.
In March of last year, the United States allowed Gonzalez to visit Cuba for two weeks to visit his ailing mother.
There has been talk of a possible swap for Gonzalez and the other Cuban agents for US contractor Alan Gross, who is serving a 15-year prison sentence in Cuba. But Washington has rejected a trade.
Gross, 63, was arrested in December 2009 for distributing laptops and communications equipment to members of Cuba's small Jewish community under a State Department contract. He was found guilty at the trial of "acts against the independence or territorial integrity" of the communist-ruled island, and sentenced to 15 years in prison.
Cuba has indicated that it is ready to negotiate Gross's release in exchange for the release of five captured Cuban spies held in the United States, but Washington has ruled this out.