De Paul was the subject of interest from Leeds United over the summer.
He told La Nazione: “Udine welcomed my wife and I from the first day, we became parents here, the way the local hospital treated my wife and daughter means a lot to me.
“We have the restaurant where we go for Christmas, our places to go for a walk, and the club made me feel important from the start. It helped me reach the Argentina squad and play the Copa America.
“These all make it difficult for me to be as happy elsewhere as I am here. But on the other hand, I like a challenge and want to grow as a player.
“I want to play in the Champions League and at a World Cup. I prepare for that every day, so I don't know what the future holds."