Robin and Barry Gibb have only performed together once since their brother and bandmate Maurice died in 2003.
When asked whether the band will ever reform without Maurice, the singer said it could happen if Barry "feels comfortable with it".
"When or where is to be decided at a time when he says yes," he told the BBC.
The duo decided to cease using the Bee Gees name following their brother's death, but Robin admitted that may change if "the time is right".
He commented: "We decided that on an emotional level at that point. Whether or not that will change, we don't know. It's a personal thing and we'll do it when the time is right.
"So it's not a no, it's just emotionally when it's right."