Reigning drivers' champion Vettel is out of contention to defend his title with three races remaining after a disappointing campaign, with the Red Bull man sitting fifth in the standings with two races remaining.
After last month's Russian Grand Prix, Red Bull's team principal Christian Horner suggested Vettel would likely require a sixth engine of the season in Austin this weekend.
The FIA confirmed on Friday that Vettel does indeed plan to use a sixth power unit - exceeding the limit by one - and, as such, will start the race from the pit lane.
"Sebastian Vettel will start the 2014 Formula 1 United States Grand Prix from the pit lane after the sport's governing body the FIA confirmed that he will use his sixth power unit of the season in Austin," read a statement on the Formula One website.
"Vettel's Red Bull RB10 will be fitted with a new engine, a new turbo, a new MGU-K and MGU-H, and new energy store and control electronics systems.
"The FIA said they had been warned by Red Bull of the changes on the Monday prior to the Grand Prix.
"Having then been notified by the Austin stewards, they confirmed in a statement that Vettel will be forced to start from the pit lane in accordance with the technical regulations."