He said: "At the moment I don't want to change anything.
"All the messages that I received said to choose with the heart and I think in the end that has been the decision. It is absolutely not about money."
But Cook says "political" issues led to Milan changing their stance on Kaka's proposed transfer.
"We met with the football club and they made it quite clear that Kaka was for sale and we made it quite clear that we wanted to bring him to Manchester City Football Club," Cook told 5 live Breakfast.
"As we got through to the next stage there were questions that were asked that they then couldn't answer.
"The political pressure they came under and the public space that they were trying to live this negotiation through maybe changed the conditions. And again, like I say, I think they bottled it.
Cook (left) and Sheikh Mansour bin Zayed Al Nahyan failed to sign Kaka
"We never met the player so it was very difficult for him to turn down Manchester City when we didn't even get to make him an offer."
Cook did meet with Kaka's father, who also acts as his advisor, and the City chief says the player was keen on a move to Eastlands.
Cook revealed he spent nearly seven hours talking with Kaka's father about the 'journey' Manchester City are embarking on.
In total, City representatives flew to Milan four times and Monday's meeting also involved three Manchester City lawyers, a senior club executive and a board member who travelled to Italy from Abu Dhabi.
"His dad said he was very interested in the project," said Cook.
"We talked a lot about a humanitarian approach and also environmental issues and the statements his son would like to make around the world.
"He is truly respected around the world not only for his capabilities as a footballer.
"Unfortunately when we talked to Milan yesterday those issues were taking a back seat and the financial demands were coming to the fore.
"It's a shame he won't be able to join us on our journey."
Milan fans protested over Kaka's proposed move to England
Cook also defended the way Manchester City had pursued Kaka and justified the huge transfer fee that had shocked the sport.
He also accused Milan of breaking a confidentiality agreement between the two clubs.
"We entered into a confidentiality agreement with Milan many weeks ago," he added.
"We've chosen not to discuss any of the details of the negotiation; it's unfair for people to make claims and statements when they don't understand the intricacies of the deal.
"This was a financial investment which showed return not only for the investor but also for the fans."
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