Infantino has faced opposition since details emerged of FIFA Forward Enterprise (FFE), which would have created a company overseeing FIFA's commercial and ticketing rights, with around 20 percent potentially sold to private investors.
Trump defended Infantino on Truth Social.
"FIFA would be making a terrible mistake if, for any reason, they even considered replacing president Gianni Infantino," Trump wrote.
"He is fantastic, having just presided over the most successful World Cup, by four times, ever presented. If he is gone, it will never be as successful or profitable again!"
His intervention follows an open letter from UEFA, Concacaf and the Asian Football Confederation (AFC) accusing FIFA of a fundamental breach of trust over FFE.
The confederations called for an independent review, while UEFA has threatened to boycott FIFA competitions and could pursue legal action.
"When trust is broken through deception, when an individual places himself above the collective that entrusted him with authority, that duty has been abandoned," the letter said.
Trump had previously said he had not discussed the plans with Infantino. Their relationship remains close, with Infantino awarding Trump FIFA's inaugural Peace Prize in December 2025.
Infantino has led FIFA since 2016 and plans to seek re-election when his current term ends in 2027.
The dispute comes weeks after the US, Canada and Mexico co-hosted the 2026 World Cup, won by Spain against Argentina.
