The Real Madrid center back, 19, is in line to earn his first cap for Les Blues in the coming weeks after France boss Didier Deschamps rewarded his performances at club level by naming him in the 24-man squad to face Georgia and Spain.
Koscielny is among those most threatened by the inclusion of Varane as the two operate in a similar role, but the 27-year-old has refuted claims he views the youngster as a rival, instead opting to focus on how the addition will benefit the squad.
"The arrivial of Varane is good competition for the squad," Koscielny told reporters. "It will force us to be better and that is a positive for the players."
The only defender named in the squad to be given a starting berth in all of Deschamps' games as coach of Les Blues is Mamadou Sakho, and, if paired alongside the Paris Saint-Germain player, Koscielny is confident the two can operate successfully as a duo.
"Both on and off the field we have a good relationship. I feel very good at his side," Koscielny said.