The 2012 champions take on Sri Lanka in the first semi-final on Thursday, and the West Indies skipper believes that his side's recent displays suggest that they can lift the trophy once again in Mirpur.
"[In the] last World Cup, the mission was to win the World Cup," Sammy told reporters. "This year it's to retain or defend the title. It's something no team has done before. We are very confident we can do it.
"Once we play the brand of cricket we played in the last three games, there is every possibility we can.
"Twenty20 is all about momentum and seizing the right opportunity. So far we've been able to do that and hopefully we can do that against Sri Lanka."
India and South Africa will meet in the second semi-final on Friday.