Musk made the comments when receiving a Golden Steering Wheel Award at a ceremony in Germany, according to media reports.
"Some of the best cars in the world are made in Germany, everyone knows that German engineering is outstanding", said Musk.
The facility will be Tesla's fifth major assembly facility and its fourth to follow the "giga" format-going large and vertically integrated with the company's energy products.
China's first plant wholly owned by a foreign carmaker - and Tesla's first outside the USA - is a crucial test of Chief Executive Officer Elon Musk's bid to prove his carmaker can sustain profitability as he bets on Chinese EV demand.
After dithering about the shift to electric mobility for years, Germany's largest vehicle groups BMW, Daimler and VW have recently announced investments worth dozens of billions of euros in the technology.
It was then reported that the Musk said that the United Kingdom wasn't considered for the new site because of Brexit: "Brexit made it too risky to put a Gigafactory in the United Kingdom", he said.
When the factories themselves aren't enough, Tesla has been known to set up (somewhat controversial) outdoor production "tents" to boost its vehicle output.
"We definitely need to move faster than the airport, that's for sure", Mr Musk said.
Over the coming years, the biggest electric auto production plants will be in Germany, France, Spain and Italy, industry analysis showed.
The premier of the state of Brandenburg, which surrounds Berlin, said Tesla was "coming with a big investment". "We lobbied for this for a long time in intensive talks and with good arguments".
Musk is now embroiled in a weird legal row with a British cave diver whom he infamously labelled "pedo guy" during the Thai cave rescue in 2018.
Tesla previously said it aimed to start production in Europe in 2021.