PANAMA CITY (AFP) - US President Barack Obama said Saturday that he did not shy away from discussing human rights concerns during his historic meeting with Cuban leader Raul Castro.

"It was a candid and fruitful conversation between me and Raul Castro," Obama told reporters after meeting the communist leader on the sidelines of the Summit of the Americas.

Obama, who met Castro for more than one hour as part of efforts to restore diplomatic ties, said he was "very direct" in expressing lingering differences over human rights.

"We are able to speak honestly about our differences and our concerns in ways that I think offer the possibility of moving the relationship between our two countries in a different and better direction," he said.

"We have very different views of how society should be organized. And I was very direct with him that we are not going to stop talking about issues like democracy and human rights and freedom of assembly and freedom of the press."