I learned this one in Girl Scouts, in Colorado, late 60's or early 70's. Slightly different from the dt version, as below:

A plea for one world
is heard in many different lands
This is a plea from a world that is hungry for peace.
When can we all live together?
When will we all work together,
Striving to make the world better
Pledging our lives to peace.

We didn't always sing it as a full round, usually just in two parts, so the second part was on "This is a plea from a" when the first part was singing "world that is hungry for". I'm not sure where that means in terms of starting, but I remember the harmony those two parts made very clearly. It might have been Russian at that. The Girl Scouts were very conscientious about trying to expose us to music from all over the world.