Germany targets storage to be 85% full by the beginning of October and 95% full gas storage sites by the start of November.
Even at 95% full storage by November, Europe's biggest economy will have two and a half months to cover heating, power, and industrial demand for gas, Müller told Bloomberg in an interview.
"We are a little bit faster than what we used to be in terms of filling up storage, but it is not a sign we can relax," he said, adding, "It should be understood as a push, instead. Let's keep it going."
Germany reached in the middle of August its target to have its natural gas storage 75% full, two weeks ahead of plans, data from Gas Infrastructure Europe showed earlier this week. As of August 16, Germany's gas storage was 77.3% full, according to the data.
Storage capacity in Europe's biggest economy is around 23.3 billion cubic meters (bcm), more than one-fifth of the German consumption of 100 bcm in 2021.
According to the head of the German regulator, the 95% target by November could be difficult to reach as some storage sites would struggle to meet the goal even if supply and demand conditions were good.
"In the best-case scenario, three-fourths of them will meet the target," Müller told Bloomberg.
The regulator isn't certain yet how the energy crisis will unfold with the coming of the winter and how industries would be prioritized and not be cut off from gas first.
Industries in Germany and the rest of Europe have been warning they may have to curtail production amid the gas crisis, which could lead to a collapse of supply and production chains.