McLaren team principal Martin Whitmarsh recently said he believes Hamilton rushed into his decision after the Sept. 23 Singapore Grand Prix and will regret the decision to end his 14-year relationship with the team. Mercedes has won one race in three seasons.
Hamilton said Thursday at the U.S. Grand Prix he was surprised by Whitmarsh's comments. Hamilton says it was an emotional decision to leave but one that he's very happy with. Hamilton says he's still giving 100 percent to the McLaren team in the final two races of the season.
Hamilton, the 2008 world champion, signed a three-year contract with Mercedes.