Vasseur, the former boss of the Alfa Romeo F1 team and Sauber CEO, started work at the helm of the Scuderia in January of this year following the winter resignation of the under-fire Mattia Binotto.
But ahead of a home race for Ferrari this weekend at Imola, the team currently occupies fourth in the constructors' championship. It led rival Red Bull going into last year's Emilia Romagna Grand Prix.
Unreliability, strategic errors and de-tuning the turbos for the latter half of 2022 led to a performance drop-off, while the new SF-23 has so far struggled for race pace and suffers from spikier handling.
But this fall down the order has not sparked any knee-jerk changes from Vasseur, with Leclerc saying the Frenchman will only now heavily intervene, having initially used his time in charge to take stock.
Asked to give an opinion on Vasseur's leadership style and any changes made, Leclerc said: "Well, I think he's just starting this process now.
"Until now, he was basically trying to analyse the situation as quickly as possible in order to do the best changes possible for the future.
"So, I think the big part of the job will be done from now on. So we will see.
"Obviously, I speak a lot with Fred and I know what his middle- and long-term plans for the team are. I'm completely behind him and I trust him fully.
"I'm sure these are the right choices and it goes in the right direction for the team. So I'm looking forward to it."
Vasseur will have to oversee a restructure of several senior positions at the team, with head of vehicle concept David Sanchez having departed for McLaren.
Meanwhile, Ferrari race director Laurent Mekies must agree on a way out of his long-term contract so that he can replace Franz Tost as AlphaTauri team principal for next season.
McLaren boss Andrea Stella, who moved into the top job at Woking on 13 December 2022 - the same day Vasseur's appointment was announced - has already overseen a major reorganisation of his team's technical department.
This included poaching Sanchez, while Stella has also identified the need to rehire former team sporting director Gil de Ferran as a non-executive consultant to help bolster the McLaren leadership structure.
