Neymar's world-record €222million move from Barca to the Parc des Princes was completed on Thursday, with the Brazil superstar presented to the media 24 hours later.
The transfer looked like it had hit a hitch when La Liga rejected the payment from PSG that met the player's release clause, but the Ligue 1 side co-operated with Barca instead to get the deal done, Neymar's lawyers going to the Catalan club's offices to hand over the money.
And Al-Khelaifi told RMC: "When that [La Liga's refusal] happened, Barcelona called me to say 'come on, let's do it together'.
"I told them we were ready. I want to thank Barca, their president, supporters, players, for everything they have done. They are one of the best clubs in the world.
"I started thinking about how to sign Neymar three years ago, and it took us a year to think about how to talk to him and Barcelona. Two weeks ago that operation really started.
"It was very complicated, we could not sleep a lot, the whole team, not only me, I thank my team for the work that has been done, many did not want to do it but we had a goal that was to sign Neymar. He's here."