Uefa will not be told "what to do" after criticism over Kylian Mbappe's contract extension at Paris St-Germain, says its president Aleksander Ceferin.
French striker Mbappe signed a lucrative new deal at PSG having been strongly linked with Real Madrid.
After the 23-year-old decided to stay, La Liga called the French club's contract offer "scandalous".
Ceferin told BBC Sport that Uefa has "financial fair play rules which are quite strict".
"Whoever will respect our rules is welcome to play in our competitions; who will not respect the rules will not," Ceferin said.
"Look not Real Madrid or anyone else will tell Uefa what to do. They are outraged from one point of view and, as much as I know, their offer was similar to [PSG's] offer."
Uefa's financial fair play rules are designed to prevent club expenditure exceeding income by more than a set amount over each three-year assessment period.
Javier Tebas, president of Spain's La Liga, has described PSG's contract offer to Mbappe as an "insult to football" and tweeted figures pointing to the club's financial losses.
PSG are owned by Qatar Sports Investments, a subsidiary of Qatar Investment Authority (QIA), the state-run sovereign-wealth fund in Qatar.
Ceferin, president of European football's governing body since 2016, says he is "tired" of complaints about the sport's willingness to allow state-run clubs.
"I've said that many times and I will say it again, tell me one argument why they shouldn't be the owners of a club," Ceferin said.
"If you say that clubs belong to the fans, don't you think that the other English clubs have owners - they have owners from the United States, some from the Middle East, they have owners from England. So it's exactly the same situation and I'm really tired of these accusations without any concrete grounds.
"I want to know who broke the rules and if you break the rules then you will be punished."
'No home games for Ukraine clubs'
Ceferin also spoke about the situation in Ukraine. Uefa has helped Ukraine's national team "find a solution" in their move to train in Slovenia before their key World Cup play-off against Scotland on 1 June.
The country's national team have not played a competitive fixture since November and have been unable to prepare normally as a result of Russia's invasion of Ukraine.
Ceferin says the displacement created by the conflict will mean clubs from Ukraine will have to find similar solutions.
He added: "For sure they will have to play away, even home matches, but it will depend on the clubs where they decided to prepare for the season. We will do whatever we can to help but it is absolutely impossible that they play at home."