Fidel Castro's niece hailed Barack Obama's support for gay marriage and the loosening of US-Cuba travel restrictions, saying: "I would vote for President Obama."
Mariela Castro, the daughter of President Raul Castro, also lamented the "small group of delinquents" who she said were preventing the warming of ties between Washington and Havana.
"I think he's sincere and speaks from the heart," Castro -- whose US trip has been denounced by opposition Republicans -- said of Obama's recent public endorsement of gay marriage.
"I think it's something that he truly believes in... If I were a US citizen, I would vote for President Obama," she added, speaking via an interpreter at her first public event in a trip to San Francisco.
But Castro said US voters must press their government to completely "remove the economic and social blockades" that have characterized the US-Cuba relationship since her uncle seized power more than five decades ago.
"It's not fair -- you can't allow a small group of delinquents to continue to manipulate and make it difficult for the US and Cuba to have a relationship," she told about 200 people gathered at a local gay rights center.
"We have a lot in common," Castro, wearing a purple scarf and flanked by several nervous bodyguards, said. "Don't let them pull us apart."
Castro, in town for an academic conference on Latin America, has been a staunch advocate for gay and transgender Cubans.
The 50-year-old trained sexologist is credited with helping to push through reforms in the Communist country, such as health plan coverage for sex-change operations.© ANP/AFP