Germany's football federation "vehemently" rejected allegations of racism on Monday, following Mesut Ozil's statements in quitting the national team.
Ozil announced his withdrawal from international football on Sunday at the age of 29, citing racism. He lashed out at the president of the German federation (DFB) for the reaction to him and Ilkay Gundogan posing for a photo with Recep Tayyip Erdogan during the Turkish President's visit to London in May.
The DFB said it "regrets the departure of Mesut Ozil from the national team" and remain "very thankful for his outstanding performances in the Germany national team shirt."
A statement added: "We vehemently reject, however -- fundamentally in view of our representatives, colleagues, clubs and the efforts of millions of volunteers -- that the DFB is being linked with racism.
"Diversity is a strength, not only in football. This is why our work on integration at all levels has been of paramount importance. Right from amateur levels through to the national team, female and male players with a background of immigration belong in the DFB. We play and live together with our different family roots, our religions and cultures. What must unite us all on and off the field is respecting the human rights which are anchored in the constitution, advocating freedom of opinion and press, as well as respect, tolerance and fair play. Acknowledgement of these fundamental values is necessary for every player, male or female, who plays for Germany.
"The pictures with the Turkish Prime Minister Erdogan therefore raised questions for many people in Germany. We are self-critical enough to admit that the DFB also contributed to this with the way we dealt with the issue, and we very much regret that Mesut Ozil felt that he was not given sufficient protection, as had been the case with Jerome Boateng, when he became the victim of racist insults. It was important, however, that Mesut Ozil, as Ilkay Gundogan before him, gives answers about this photo, regardless of the way the tournament in Russia ended. In the DFB, we win and we lose together, as a team.
"The DFB would have been pleased had Mesut Ozil wanted to remain part of this team. He has decided differently. The DFB respects that and it is also part of our obligations as an association to act respectfully towards our worthy national team players and [this is why] we do not comment on some remarks, be it their tone or content, in public.
"The DFB regrets Mesut Ozil's retirement from the national team. That does not change, however, the determination the association has to continue to pursue, firmly and with deep conviction, its endeavours in successful integration work."
Ozil, who crashed out with Germany in the group stages of the World Cup, had posted a lengthy statement on social media on Sunday insisting that he had done nothing wrong in meeting Erdogan and said he will not represent Germany.
"It is with a heavy heart and after much consideration that because of recent events, I will no longer be playing for Germany at international level whilst I have this feeling of racism and disrespect," he wrote. "I used to wear the German shirt with such pride and excitement, but now I don't."
Anti-racism organisation Kick It Out said in a statement that Ozil's experience was not unique to those with roots from other other countries.
"Following Germany's exit from the World Cup, the racist treatment Mesut Ozil has faced by elements of their media, supporters and wider society is extremely disappointing -- but is also reflective of the experience of a number of footballers across Europe from mixed heritage backgrounds," the statement said.
"Mesut Ozil has been treated disgracefully and we have contacted Arsenal to offer our support to him at this time. Those who have driven him to consider international retirement should be ashamed of themselves and his case should encourage all of football to reflect on how the game treats footballers from mixed heritage backgrounds."
Meanwhile, Bayern Munich president Uli Hoeness criticised Ozil both for his decision to leave the team and his recent play, saying: "I'm glad this nightmare is over. He's been playing crap for years."
ESPN FC correspondent Ben Gladwell contributed to this report.