Activists in Fiji say its Health Ministry's policy of preventing homosexual men from donating blood was unconstitutional and discriminatory.
But the Ministry said its policy was informed by WHO guidelines.
WHO HIV Medical Officer Madeleine Salva said the guidelines also recommend deferring blood donation from people engaging in other high risk sexual behaviours such as having multiple partners, sex workers and their clients.
She said the guidelines don't single out gay men.
"All of us doesn't want to have challenged the sanctity of the safety of the blood supply so that is just the main thing. It's not about discriminating a specific person or a specific group," he said.
Dr Salva said countries should also give out information about who was eligible to give blood so people can self-defer.