If you believe websites, then he also said:
“In the first six to twelve months of a war with the United States and Great Britain I will run wild and win victory upon victory. But then, if the war continues after that, I have no expectation of success.”
I'm more inclined to interpret his statement as a testiment to our industrial capability. Of course, without the context of his argument, it's kind of pointless to debate, IMHO.