Kimi Raikkonen says Ferrari has simply followed a pre-determined strategy in its decision to fit a new engine ahead of the United States Grand Prix, suggesting it was months in planning.

Raikkonen and team-mate Sebastian Vettel will take the hit of a ten place grid penalty in Austin this weekend after Ferrari opted to change its engines, explaining it as an attempt to maximise its performance in the final four rounds.

Indeed, though many suggested Ferrari could have held off in favour of giving Vettel more of a fighting chance in the standings and because of the rain this weekend, Raikkonen says the decision - which he supports - was ultimately taken before the season had even begun.

"It was made already before the season started so we have been doing as we planned already in the first part of the year and I think it's been the correct choice.

"We've been doing good things, it's one of those things that we planned and we are going to stick with it and I think it's the correct things, so whatever the conditions are doesn't change that much."