Chelsea have condemned all discriminatory behaviour and started an internal disciplinary procedure in the wake of Argentina's derogatory song about French players, the club said in a statement.
The French Football Federation (FFF) announced on Tuesday it would file a legal complaint over "racist and discriminatory remarks" made by Chelsea player Enzo Fernández and his Argentina teammates about France's team after Sunday's Copa América victory over Colombia.
"Chelsea Football Club finds all forms of discriminatory behaviour completely unacceptable," a club statement said on Wednesday.
"We are proud to be a diverse, inclusive club where people from all cultures, communities and identities feel welcome."
Following Argentina's 1-0 win over Colombia in the final, Fernández posted a video on Instagram that was widely viewed on X. The video showed the Argentina players singing offensive chants that singled out France players of African heritage.
The same chants -- by some Argentina fans -- emerged before France and Argentina met in the 2022 World Cup final, which Argentina won.
France defender Wesley Fofana displayed his discontent with his Chelsea teammate and reposted the video, citing the chant as "uninhibited racism."
Chelsea and France forward Christopher Nkunku followed Fofana, saying on X: "God bless them," talking about the Argentinean team's derogatory words.
Fernández issued a statement of apology on Instagram admitting the song "includes highly offensive language" but added "those words, do not reflect my beliefs or my character. ... I stand against discrimination in all forms and apologise for getting caught up in the euphoria of our Copa America celebrations."
French sports minister Amélie Oudéa-Castéra wants FIFA to take action. She replied to a L'Equipe story about the derogatory chants, writing on X: "Pathetic. Behaviour that is all the more unacceptable if it is repeated. @FIFAcom: a reaction?"
FIFA also said it was also looking into the incident after the French federation pledged to file a complaint with the sport's world governing body over "racist and discriminatory remarks."
FIFA president Gianni Infantino has said football and its 211 national federations must have a zero tolerance approach to racism and in May committed to relaunching a task force to monitor incidents.
"FIFA is aware of a video circulating on social media and the incident is being looked into," the governing body said Wednesday. "FIFA strongly condemns any form of discrimination by anyone including players, fans and officials."
It is unclear what jurisdiction FIFA has over the incident on a team bus after a tournament, but the governing body likely could act if the Argentina federation's handling of the case is considered unsatisfactory.
Julio Garro, Argentina's undersecretary for sports, said on Wednesday he felt Argentina football federation president Claudio "Chiqui" Tapia as well as team captain Lionel Messi should issue apologies for the chanting.
"This leaves us, as a country, in bad standing after so much glory," Garro said in an Argentina radio interview.