Also, a billion dollars is cheap. US federal budget is basically 3000 billions. It's not even 1% of the budget.
Moreoever, it's useless to Ukraine. 1bil doesn't cover 1 months' spending with all the troubles this "mini aggression war" caused and all the damage that the previous government did. Consider this, under Yanukovych, almost 37bil euros went "missing"... well, went into the pockets of politicians and their clientele which is why Ukraine is in big trouble now, economically.
The EU plans to give a 15-20bil euros bailout to Ukraine. those are the numbers circulating. We'll know more in 2 days.