Laurent Mekies hailed Christian Horner's achievements with Red Bull as he conceded it still feels "unreal" to be in charge of the team.
Mekies succeeded Horner as Red Bull's team principal earlier this week.
Horner was dismissed on Wednesday, ending a 20-year spell in charge of the team, during which time Red Bull won six constructors' titles and eight drivers' championships in Formula One.
Red Bull sit fourth in the constructor standings in 2025, way off the pace set by leaders McLaren, while four-time reigning champion Max Verstappen is third among the drivers.
"It still feels unreal to be here and not to see him [Horner]," said Mekies, as quoted by Sky Sports.
"It would be impossible to underestimate the size of the achievement this team has had under 20 years of Christian's leadership.
"I met him 20 years ago when he was the youngest team principal in F1 and it's unbelievable to see how he's turned this place to the level it is now.
"That journey, the many titles and wins. Christian is also the guy, with Helmut [Marko] and Oliver {Mintzlaff] that brought me back to the Red Bull family two years ago. All the first thoughts are with him today."
While Mekies is not underestimating the challenge of getting Red Bull back to the pinnacle of F1, he sees plenty of reasons to be positive.
"I look at this team as most outside look at them, we see the very best people in the world at what they do," he said.
"That's what this team is, even from being a competitor previously you look at Red Bull Racing as being the sharpest team, having managed to accumulate the best talent to work together.
"It is a privilege to join the team and the focus will be on making sure all the talented people here have what they need to perform at their best, because they are already the very best.
"We will be focussing on that and making sure the Red Bull energy is flowing through the team.
"We are not underestimating the challenge ahead, we will need everybody and we will go about it together and I am sure with everyone's contributions we will tackle this challenge."
