White was omitted from Gareth Southgate's 28-man squad for the upcoming Nations League fixtures against Italy and Germany, England's final two fixtures before their World Cup campaign begins in November.
The 24-year-old pulled out of the England squad in May due to a hamstring issue but has enjoyed a strong start to the season, playing right-back for the Arsenal.
Various reports suggested White was once again struggling with injury but Arteta revealed he has instead been dropped.
Asked outright if White was fit, Arteta replied: "Yes."
Prompted to clarify whether it was a selection issue rather than injury that saw White left out by England, he added: "Yeah, yeah. He's fit.
"But that's Gareth's decision and his coaching staff. What I can tell you is that whenever Ben gets the call he'll be ready."
Eyebrows were raised when White - who can also play centre-back and defensive midfield - was dropped, especially as out-of-form Manchester United captain Harry Maguire was one of 12 defenders included in Southgate's squad.
"He's played in both positions, sometimes he's been selected, sometimes no," added Arteta.
"I think if you have a versatile player who can play at the level Ben can, as both a central defender and full-back…in my opinion, that's something any manager would want, especially when you go to a tournament where a lot of things can happen."
It remains to be seen if White will feature away at Brentford on Sunday as Arsenal look to head into the international break with a victory that will keep them at the top of the Premier League.
The £50million defender had a chastening Arsenal debut as the Bees won the corresponding fixture on the opening day of last season.
Arteta used a tweet from Ivan Toney after the win as motivation for the return game at the Emirates Stadium, showing his players in the dressing room before kick-off.
"Anybody can write whatever they want. I'm here to judge it, to read it if it's necessary and use it in the way that I feel is most powerful," the Spaniard replied when asked if he felt the tweet was disrespectful.
Pushed on whether he would be happy for any of his players to send similar tweets, he replied: "I try to have my players act in a certain way and I'm happy with the way they act."