The Dutch manager was unveiled as the new Red Devils boss at a press conference on Monday, arriving from Ajax following the end of the Premier League season.
United suffered yet another disappointing campaign under Ole Gunnar Solskjaer and then interim boss Ralf Rangnick, finishing sixth and missing out on Champions League qualification.
Speculation is rife over the future of Ronaldo, who has one year left on his current United contract.
Since returning to the club last summer, the iconic forward has scored 24 goals in 39 appearances in all competitions, but has been linked with a move away as part of a major restructure at the club.
However, according to a guarded Ten Hag, Ronaldo is expected to be at the club next year.
Asked if Ronaldo will be a part of his plans, Ten Hag said: "Of course."
He was then asked what he can expect from Ronaldo, to which he laughed and replied: "Goals."
When pressed on the Portugal star's leadership responsibilities, the Dutchman said: "I will speak to Ronaldo about that before I speak to you."
While bringing in new players will be a big focus for Ten Hag, the Dutch boss confirmed to the club's official website that he'll be looking at how he can get the best out of his current group given their successes in the not-too-distant past.
Asked about his plans for the coming weeks, he said: "First, we have a break.
We will start pre-season on 27 June and I will get a few of the squad, [a few] of the individual players.
"In certain positions we want to renew the squad, but as I said, one year ago, this squad was second in the league, so there is potential and I'm really looking forward to co-operating with the squad."
He added: "Everywhere I was in my career, I have high demands on my players.
"I expect them to fight and give 100 per cent. I already mentioned that only good is good enough.
"No, not only that - we have to do better and they have to co-operate. They have to be unified, to form a team, and to battle the opponent."