Putin initially offered assistance in investigating Monday's twin bombings in Boston that killed three people and wounded more than 170, saying in a condolences note Tuesday that the international community should come together to fight terrorism.
He followed up on that Thursday evening while opening the Ice Hockey Under 18 World Championship in Sochi.
Speaking before the game of Russian and U.S. teams, Putin called for a moment of silence and offered condolences. He said that the fact that the Boston attack occurred during a major sports event made it "particularly disgusting."
Russian officials have pledged to do everything necessary to ensure security of the 2014 Winter Olympics in Sochi.