Speaking to around 20,000 employees Muller stated that "to be perfectly frank: this will not be a painless process" with the company now focussed on its investigations, as well as determining how best to fix the roughly 11 million affected vehicles and its reputation.
With that in mind, the new chief executive has "initiated a further critical review of all planned investments", with programmes that are "not absolutely necessary will be cancelled or postponed". Muller hinted that there might be job losses ahead as the company sets about "intensifying the efficiency programme".
Volkswagen's CEO promised "swift and relentless clarification", but cautioned that as "we are dealing with four brands and many model variants, care is even more important than speed".
Just days after Volkswagen admitted to US authorities that it had installed a cheating algorithm on diesel cars with the EA189 engine, the company set aside 6.5 billion euros ($10.3 billion) to deal with legal, remediation and other costs associated with the affair.
Backing up commentary from many pundits, Muller said: "Apart from the enormous financial damage which it is still not possible to quantify as of today, this crisis is first and foremost a crisis of confidence. That is because it is about the very core of our company and our identity: it is about our vehicles."
Volkswagen promised that "over the coming days" it will begin contacting and informing customers on how it will upgrade their EA189-engined cars to meet the relevant emissions standards.
In a note of optimism, Muller said that "in many instances a software update will be sufficient". However, other cars will "require hardware modifications".
The company will also launch websites in the near future, so that customers can check, via chassis numbers, whether their cars are affected.
On the weekend, Volkswagen Australia announced that it would halt the sale of cars fitted with the 1.6- and 2.0-litre EA189 diesel engine. Simultaneously, Audi Australia confirmed that it will suspend sales of models equipped with the 2.0-litre EA189 motor.