A gay advocacy group on Thursday said the U.S. government has refused to allow the daughter of Cuban President Raúl Castro to travel to Philadelphia next month to participate in its annual event.

Equality Forum Executive Director Malcolm Lazin said in a press release that Mariela Castro, executive director of the Cuban National Center for Sex Education (CENESEX,) several months ago accepted an invitation to speak on a panel at the University of the Arts on May 4. She was also scheduled to accept an award at the group’s annual dinner that will take place later that same day at the National Museum of American Jewish History.

Lazin said the State Department issued a visa to Castro that allowed her to attend meetings at the United Nations in New York City. He said the U.S. government refused to allow her to travel to Philadelphia to attend Equality Forum that will highlight Cuba.

Lazin told the Washington Blade on Thursday the Cuban government attached Equality Forum’s invitation to its application for a visa that would have allowed her to attend the event.

He said he reached out to a senior member of Pennsylvania’s congressional delegation to ask if the State Department could reverse its decision. Lazin told the Blade neither “that member of Congress nor Equality Forum has gotten a response to that.”

“Over the past 11 years, Equality Forum has invited leaders of the featured nation to attend. For those who needed a visa, all past visas have been approved,” he said in a press release. “It is shocking that our State Department would deny Ms. Castro travel to a civil rights summit — especially one held in the birthplace of our democracy that enshrines freedoms of speech and assembly.”

Mariela Castro, whose uncle is former Cuban President Fidel Castro, has spearheaded a series of campaigns over the last decade to prevent the spread of HIV/AIDS and promote acceptance of LGBT people on the island.

She successfully lobbied the Cuban government to begin offering free sex-reassignment surgery under the country’s national health care system in 2010. Mariela Castro has also spoken out in support of marriage rights for same-sex couples in Cuba.

Mariela Castro in May 2012 appeared on a panel with Rea Carey, executive director of the National Gay and Lesbian Task Force, in New York while she and other Cuban scholars visited the United States. She also met with LGBT advocates in San Francisco during the trip.

In spite of this progress, those opposed to the Cuban government maintain LGBT rights advocates on the island continue to suffer harassment and discrimination.

Cubanet reported last September that Cuban security officials detained Leannes Imbert Acosta of the Cuban LGBT Platform, an umbrella organization of 12 of the island’s independent LGBT rights groups she co-founded in June, as she left her Havana home to deliver to CENESEX materials on a planned exhibit on forced labor camps to which the government sent more than 25,000 gay men and others deemed unfit for military services during the 1960s. Cuba Archive, a New Jersey-based organization that documents the Cuban government’s human rights abuses, said during a panel on LGBT rights on the island it hosted in New York a few days after Imbert’s reported detention that authorities confiscated her materials and pressured her to cancel the planned exhibit before they released her.

Imbert claimed during the same event that CENESEX did not investigate the camps known as Military Units to Aid Production — or UMAPs in Spanish — as she said Mariela Castro had promised.

The Cuban government in 1979 repealed the country’s sodomy law, but Cuban-born poet Emilio Bejel and others who took part in the Cuba Archive panel stressed authorities continue to use public decency and assembly laws to harass LGBT Cubans.

Cuba also forcibly quarantined people with HIV/AIDS in state-run sanitaria until 1993.

Ignacio Estrada Cepero, a gay man with HIV who founded the Cuban League Against AIDS in 2003, stressed during the same Cuba Archive panel in New York those with the virus on the island continue to face discrimination. He also claimed some with HIV/AIDS remain in prison for what he describe as the crime of “pre-criminal social dangerousness.”

Observers have credited Cuba’s condom distribution campaign and sexual education curriculum for producing one of the world’s lowest HIV infection rates. Cubans with the virus have access to free anti-retroviral drugs, but Estrada complained during the Cuba Archive panel they don’t always reach those who need them.

“We don’t have access to medication and our rights are violated,” he said.

Lazin conceded that Cuba is not “a perfect nation,” but stressed “neither is the United States.”

“There are those who are being critical of necessary changes within Cuba [should be] given the right to express those views of both generally and to their government,” he told the Blade. “That to me is what freedom of speech and freedom of assembly is all about. As a country that has pioneered democracy and champions democracy, the fact that we would not allow Mariela Castro to come to Philadelphia for a civil rights summit and open herself to questions from the public and the press on LGBT rights in Cuba to me is a sorry day for the country I love.”

A State Department spokesperson declined to comment on Equality Forum’s claim, citing the confidentiality of visa records under U.S. law.

CENESEX did not immediately return the Washington Blade’s request for comment.