The four-time Ballon d’Or winner has won every honour with his club side Barcelona in Spain and is widely regarded as one of the greatest players of all time at the age of 26.
But despite his phenomenal success with the La Liga giants, some critics claim that until Messi replicates his club success on the international stage with Argentina, he cannot claim his place among the real greats of the game.
However, Ronaldo has dismissed that suggestion, instead insisting that Messi has already done enough to be labelled a football god.
“He can win that [the World Cup]. He has not retired yet, has he? And he is only 26,” the three-time World Player of the Year told The Times of India.
“Moreover, in the history of football, there are players who did not win the World Cup but are considered as great as any other footballer.
“If you win the World Cup, it gives your status a boost. However, if you cannot, you can still be among the all-time best.
“I saw him [Messi] in Barcelona in his early years there and spoke about him with Ronaldinho. Ronaldinho was full of praise for the boy and when we saw him, we knew why Ronaldinho was so appreciative."
Ronaldo added: “Messi is really a different class. To win four consecutive Ballon d'Ors is a great achievement.”
The Brazil icon also spoke about his namesake, Real Madrid winger Cristiano Ronaldo, and backed the 29-year-old star to fire Portugal to World Cup success this summer.
“He had given us, the Madridistas, what we were looking for, La Decima. I was so happy for him when he won the Ballon d'or this year. He deserved it,” Ronaldo said.
“For Portugal, he has been playing well. He can set the grass on fire with his speed and powerful strikes. His headers are powerful too and he always out-jumps the defenders.
“Portugal are in a tough group but Cristiano should help his team qualify for the knockout and then, it can be anybody's game.”