"It's not easy, after everything I have been through, to sit down and write these lines," the Manchester City man said in his letter.
"There have been days and weeks of reflection and analysis to take the decision to end my time with the Spanish national team. Without doubt, it is one of the most difficult choices of my career.
"The national side has given me everything and allowed me to grow as a player and a person since the youth categories.
"I leave happy for everything achieved, I lived and dreamed with a team that will always be remembered and I am bringing to and end a time filled with emotion and moments that I will always remember, such as Luis Aragones, the maestro we will never forget."
Silva played for Spain for 12 years, scoring 35 goals in 125 caps and winning the World Cup and two European Championships.
13 August 2018