Ronaldo says he is retiring from soccer because he can't stay fit anymore, ending a stellar 18-year career in which he thrived with Brazil and some of Europe's top clubs.

The 34-year-old Ronaldo said Monday a string of injuries in the past two years had kept him from performing at a high level with Brazilian club Corinthians.

Ronaldo won two World Cups and holds the record for most goals scored in the tournament.

With his uncanny sprints toward the goal and an incredibly accurate finishing touch, he captivated fans everywhere he played, including Barcelona, Real Madrid and Inter Milan.

All despite having to come back from three serious knee injuries that threatened to end his career earlier than expected.