Dortmund’s chief executive Hans-Joachim Watzke said the midfielder can leave in the summer transfer window, and Al-Khelaifi said he would be interested in signing him.
“What a player. Honestly, England are lucky to have him … and he’s one of the best players in the tournament,” he told Sky News.
“Amazing and you see his first World Cup — calm and relaxed and confident.”
“Everyone wants him. I’m not going to hide it. But I respect he’s in his club and, respect if we want to talk to him, we talk to the club first.”
Ronaldo is a free agent after he mutually agreed to terminate his contract with United in November following a controversial interview before the World Cup.
“The three players that we have [Messi, Neymar and Mbappe], it’s very difficult, but I wish him all the best,” Al-Khelaifi added.
“He’s fantastic and he’s still an amazing player.”
The 37-year-old was dropped from the starting lineup for the round-of-16 clash after a fallout with Portugal coach Fernando Santos.