Vasseur was responding to ongoing speculation about Leclerc's growing frustration at Ferrari, amid suggestions that he might look elsewhere at the end of his current contract.
The Frenchman stressed that successful team projects are always built around the contribution of a driver, citing examples that included the Michael Schumacher era at Maranello, and insisted that Leclerc is fully immersed in the current rebuilding programme.
"He's clearly part of the project, that means he is not a spectator of this," said Vasseur. "He is involved in the development of the team, he is part of the development, because he's developing himself.
"He is a performance contributor on track and out of the track. And as long as he will play this role, we are on a good path.
"It's true in every single team that you are always building a team around the driver. If you ever look over the last 20 years or even more, all the successful top stories in F1 took time. But it was always a team built around someone, a driver. It was true with Lewis [Hamilton] at Mercedes.
"And it was true before with Michael at Ferrari, it was true with [Fernando] Alonso at Renault, it was true everywhere. You can find tonnes of examples.
"For sure that Charles is an important pillar of the performance, and he has to play the role in the car, outside of the car, to be a performance contributor. And he's fully supportive of this part of the job. And I'm really convinced that it's also a personal commitment from himself."
Source: Autosport