My question is "is it illegal to manufacture an airliner in the US without FAA approval, providing it's never actually flown in the US?" It's somewhat abstract

My question is "is it illegal to manufacture an airliner in the US without FAA approval, providing it's never actually flown in the US?" It's somewhat abstract, but it's an interesting question to me, which is why I asked. Does the FAA's authority to regulate aircraft construction come from Congress specifically delegating authority over aircraft construction to them- or does the FAA only effectively have the ability to control construction because they can prevent the aircraft from flying in US airspace?