Portugal failed to make it out of the group stage at the World Cup in Brazil earlier this year, with Ronaldo failing to impress on the biggest stage of all.
The Real Madrid superstar believes the country's relatively small talent pool has been holding it back, but is confident of a change of fortunes ahead of Portugal's opening Euro 2016 qualifier against Albania on Sunday.
"It's not easy," he told the Telegraph. "Compare the quality we have at Real to the national team, and it's not the same.
"I'm together with my national team-mates only sometimes.
"We have only 10 million people in Portugal, so to find the top players is a struggle. This is the key to why Portugal have never achieved any important trophies, like the World Cup or European Championships.
"But we still believe. We have to be confident that one day it will happen. Maybe at Euro 2016, that's the time we’re going to win something.
"I'm looking forward to that. I think it's possible.”
In contrast to his international experience, Ronaldo had a glittering season on the club front last season.
As well as winning the Ballon d'Or, the 29-year-old was part of the Real team that won both the Copa del Rey and a 10th UEFA Champions League crown - La Decima.
"Well, it was a fantastic year," he added. "We won the Champions League, we won La Decima, the trophy that Real Madrid had been looking for a lot.
"So this season we're going to try to do the same, to win the Champions again, to win La Liga.
"And in terms of individual achievements I'm going to try to break my own records. I know it's tough, but I'm going to try."
