You will have to wait until it is close to release or after release.
The current plan is to, at a minimum, support German, French, and Russian as well. However, this process won't begin prior to release because there's a lot of text expected in the game (over 100,000 words which is, in effect, a book's worth of text).
That's because each race has its own technology tree, will have its own diplomacy conversation types, random events, and countless other small things. Imagine translating Civilization to other languages if each civilization had their own tech tree with its own description.