Kroos played his last game for the German national team when England defeated them 2-0 at the Wembley stadium on Tuesday, leading to their exit from the Euro 2020.
The Real Madrid midfielder featured 106 times with 17 goals and 19 assists for Germany and was a key cog in Joachim Low's side that won the 2014 World Cup in Brazil, having defeated Argentina 1-0 in an extra-time thriller.
"I have played 106 times for Germany. There will not be another time.
"I had already made the decision to retire after this tournament for some time. It had been clear to me for a while that I will not be available for the World Cup 2022 in Qatar.
"I would have dearly wished, and I gave everything again, that there would have been 109 internationals in the end and that this one big title, the European Championship, would have been added at the end.
"It was was a great honour for me to be able to wear this jersey for such a long time," he added. "I did it with pride and passion."
The midfield dynamo with four Champions League medals to his name will now concentrate on his club career, stressing he wants to focus "fully on my goals with Real Madrid for the next few years."
Germany are eager to win a trophy after their Fifa Confederations Cup triumph in 2017 and have been experiencing inconsistency thus far, a situation many see it as the reason why Low lost his job.
After 15 years as the manager for the national team, Low has been replaced by former Bayern Munich manager Hansi Flick who's expected to bring in fresh ideas into the German squad.
