The seven-time champion is a supporter of Vasseur, who was instrumental in signing him.
Speaking during the drivers’ news conference before this weekend’s United States Grand Prix, Hamilton said: “It is a little bit distracting for us as a team. The team have made it clear where they stand in terms of re-signing Fred.
“Fred and the whole team are working really hard on a future for the team.”
Vasseur’s contract was due to expire at the end of this season, but it was renewed just two and a half months ago.
Ferrari tend not to comment on stories about the future of the team, considering it media speculation.
But when reports linking Horner to the team first emerged in the summer, Ferrari used channels to communicate to the media that there was no truth in the claim. The company’s position has not changed since.