The former Ajax defender completed his move to Stamford Bridge on Sunday.
Hato joins Chelsea for a fee of £37m and he has signed a contract to 2032.
The 19 year-old said, "I'm very excited, I'm so happy to be here.
"I thought a lot about my future and wanted to take the next step in my career. Chelsea is the best place for me to do that so I'm very happy."
Hato also explained, "I was really thinking about my future and this is what I wanted. I think I will be a good fit for the way Chelsea are playing, so I was sure about taking my step to Chelsea.
"For sure it was a big decision. I played seven years at Ajax and for me it was home – the people, the players, the coaches, the culture. So it was not easy to leave, but my feeling was that at this moment I needed to make a step to the biggest club in the biggest competitions, and for me this was the right decision at the right time."
Hato added, "This was for me the right time to make a big step, to come to the Premier League, to come to Chelsea. And now I’m here!"