The move, heavily championed by European governing body (UEFA) president Michel Platini, was confirmed during the first meeting of FIFA's new Strategic Committee, chaired by Platini in Zurich on Tuesday.
A FIFA spokesman said the precise role of the two extra officials, including their general positioning, would be determined in the run-up to the competition.
FIFA had already announced that it would use the tournament to continue tests on goal-line technology developed by ball manufacturer adidas, using a chip in the match ball to determine whether shots had crossed the line.
The International Football Association Board (IFAB), which governs the laws of football, gave provisional backing to the use of goal-line technology during a meeting in March.
IFAB insisted that the technology had to be instantaneous and 100 percent accurate with decisions transmitted only to the match officials.
DISPUTED ISSUES
Tuesday's Strategic Committee meeting also involved talks on disputed issues, including the future look of the international match calendar and the row over compensating clubs whose players were injured on international duty.
The committee said it had agreed to set up working groups to discuss both issues.
In a statement released after the meeting, FIFA said there were "serious concerns" regarding the issue of third-party ownership of players
"The FIFA administration is working on a simple and effective solution... that will be submitted to the world governing body's legal committee," it added.
FIFA president Sepp Blatter meanwhile "expressed sheer dismay" at a decision by the Court of Arbitration for Sport last August, allowing Spanish side Granada 74 effectively to buy a place in the country's second division.
Arguing that the verdict "opened the doors for the American franchise system to football," Blatter said FIFA would take "immediate action to stop this loophole by passing appropriate regulations."
Granada 74 earned promotion from the Andalucian league to the regionally based Tercera division (fourth tier) last season. But they were catapulted into the second division when club president Carlos Marsa took advantage of new professional league regulations to buy second division Ciudad de Murcia for an estimated 20 million euros (13.8 million pounds).
He then moved the club's headquarters to Motril 70 km south of Granada.
