The source lists yield in thousand tons. I think you forgot to tack on those three extra zeros.

Raw rice grains are made up of a white grain surrounded by a bran and inedible husk. Rice is milled to remove the husk to make brown rice. It can be milled more to remove the bran to make white rice. Obviously, this process will cause the rice grains to lose ~30% weight, reducing the milled yield weight from the raw yield weight.

I think your choice of 700,000 tons for Russia's total edible yield makes more sense. If Russia gave the DPRK raw rice, the DPRK would have to mill it all anyways.

Either way, this supposed deal is very silly. Russia barely grows any rice, and this list says the DPRK actually grows more rice than Russia.

Perhaps the propagandist misspelled wheat as rice?