My old school is involved with a charity working with children affected by the disaster in Chernihiv (Chernobyl) in Ukraine and Belarus. Every Christmas we send Shoeboxes of presents and in the summer the charity brings children over to England to get them away from the radiation so their bodies can have a chance to heal and they stay with Parents and teachers from the school. This summer I'm going to be involved helping take them to visit museums, iceskating, picknics ect. Although there will be an interpretor it would be very helpfull if I can also comunicate.
The children this year are comming from southern Belarus.
I have been learning Russian now for some years on and of but I want to focus on Ukrainian. I'm wondering if I will be likely to comunicate with Belarussians using Ukrainian or would I do better with Russian? I know that Ukrainian and Belarussian must be quite similar, but are they likely to be similar enough or will they understand Russian better (as I expect it's very well know in Belarus).
I'm also wondering weather or not I'd be better of focussing on learning Russian for traveling in eastern Europe/Russia? I perticually want to visit Ukraine and Russia and I'm wondering how well I could get by in Ukraine only knowing Russian.
Any advice would be great!

Спосибо

*русский
*спасибо

I don't know about Belarus, but I know there are a lot of Russian speakers in Ukraine (either as a first or second language).