Novak Djokovic has said he disagrees with Roger Federer and Rafael Nadal's stance not to support the formation of a new players' association but insists he respects their decision. Nadal and Federer called for "unity, not separation" after Djokovic revealed at the weekend that he was spearheading a controversial breakaway union for professional male players. "I respect, of course, completely their choice that they don't want to be involved in it at the moment," said Djokovic after progressing to the US Open third round with a four-set win over Britain's Kyle Edmund. "They don't think it's the right time. That's fine. That's their opinion. I disagree with that." Djokovic said his idea was not a new one and that he was just "following up on what the previous generations have attempted to do". "For a players' association, it's always the right time, and it has been the right time for the last 20 years. Somehow it was never really accomplished, never really realized. Right now it is. We are moving forward," he said. Djokovic recovered from a set down to defeat Edmund 6-7, 6-3, 6-4, 6-2 in the second round of the US Open on Wednesday. He said it had "not been easy" dealing with the storm caused by his announcement during his bid for an 18th Grand Slam. But he also insisted the new association would not form a rival tour to the ATP or boycott tournaments. It is intended as a "platform" to give players a louder voice, Djokovic explained. "We have highest of intentions for players. I mean, this is only thing we have. We don't want to fight anyone. We don't want to fight for existence with ATP, ITF (International Tennis Federation), or any other governing body. "I think there is a place for players association. There always has been a place for players association," he said. "It's just that right now obviously there are people that just don't want that to happen because there's a certain structural system in place that has been protecting them. I understand that. That's fine."