The former Sweden striker, 37, did not sit on the fence in his response to Ronaldo's suggestion that he left Real Madrid for Juventus because he enjoyed a "challenge".

Speaking in December, following a £99.2m switch to the Italian champions in the summer, the 33-year-old Portugal captain called upon former La Liga rival Lionel Messi to leave Barcelona, having been at the club since 2001.

"I've played in England, Spain, Italy, Portugal and for my national team, while he's still in Spain," said Ronaldo.

"Maybe he needs me more. For me, life is a challenge. I like it and I like to make people happy."

But now Ibrahimovic, a former Juve forward, has hit back, saying: "Ronaldo talks about challenges but he decided to go to a club who have been winning the Serie A title with their eyes closed.

"Why did he not choose a club from a second division a few years ago? Try to become a champion with such a second-division [club] and lead them to the highest level.

"Moving to Juventus is not a challenge at all."

Juve have won the Italian top-flight for the past seven seasons and are nine points clear at the top this term, with Ronaldo scoring 15 goals in 25 appearances for them.

Ibrahimovic, who won league titles with five major European clubs and spent time in the Premier League at Manchester United - one of Ronaldo's former clubs - did not include the Portuguese in an all-time XI he named in December.

He has previously said Ronaldo is not a "natural talent".