"I will close my cycle (with the Portugal team) at the end of the World Cup, due to my age and because it is tiring," the 32-year-old told Brazil's Radio Globo.
Deco started his Portugal career in a friendly against his native Brazil in March 2003. He went on to win 72 caps and score five goals for the Iberian country. He played in the European championships in 2004 and 2008 and the World Cup in 2006.
"The responsibility is always big. For me the 2006 side had more experience while the current one had younger players. Technically they are similar," he said.
The Chelsea player, who won the Champions League with Porto in 2004 and Barcelona in 2006, added that he planned to return to Brazil to play at club level after the end of next season.
The World Cup runs from June 11 to July 11.
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