The Portugal captain concedes that, though his team gave their all in the 2-1 win over Ghana, they simply could not score the goals they needed to have a chance of progressing
The Seleccao secured a 2-1 win in their final Group G game, with Ronaldo scoring late on to add to a John Boye own goal, while Asamoah Gyan replied with a header.
However, though the Portuguese finished level on points with the United States, they fell short due to an inferior goal difference, something that Ronaldo regretted that they were not able to correct.
"It was a good game," the 29-year-old was quoted by Record.
"We needed to win, which was something we could do. We created many chances but could not finish. We had to score three goals and depend on Germany. We weren't able to."
Portugal were unable to match their performance in the 2010 South Africa World Cup, where they were knocked out in second round by Spain, and Ronaldo revealed his frustration at not putting their chances away and taking advantage of the United States' defeat.
"We did our best, but what happened was all that was possible," he continued.
"Judging by the amount of chances, we deserved a little more. We leave with our heads high. We did our best but it was not enough."