FIFA President Gianni Infantino told the 12 breakaway European Super League clubs on Tuesday that they could not be "half in, half out" of the established football system and must face up to the reality of their decision.
"If some elect to go their own way then they must live with the consequences of their choice," Infantino told UEFA's congress in Montreux, Switzerland.
"They are responsible for their choice - concretely this means, either you are in, or you are out.
Real to wait for Mbappe after he tells PSG he will not sign new deal - Paper Round
You cannot be half in and half out. This has to be absolutely clear.
The FIFA head, a former UEFA general secretary, repeated his opposition to the breakaway project.
- 'Huge mistake' - Ceferin berates 'arrogant', 'ignorant' Super League club owners
- 'Not a sport' - Guardiola cut short by City after slamming Super League
"We can only and strongly disapprove of a Super League which is a closed shop, breakaway from current institutions," Infantino said.
'Come to your senses' - Ceferin berates 'arrogant' and 'ignorant' Super League club owners
"No doubt whatsoever of FIFA's disapproval. Full support to UEFA.
"We hope that everything will go back to normal, that everything will be settled, but always with respect, always with solidarity and with the interests of national, European and global football."
Additional reporting from Reuters
'We were not involved' - Furious Klopp reacts to Super League furore
Opinion: Could Rashford and Sancho stop people hating Man Utd?
'This is where I belong' - Man Utd confirm Sancho transfer