There were two separate gas discount agreements with Russia and Ukraine, one discount for the Black Sea Fleet lease and another as part of the December 2013 loan package designed to keep Ukraine out of default.
After Yanukovitch was overthrown the Russians halted the loan package and as of April 1st the gas discount associated with it.
Russia later on decided they no longer would abide by the Black Sea Fleet agreement, which they had pre-paid a portion of, because Ukraine still wasn’t paying anything for the gas they consumed and because Crimea is no longer part of Ukraine.
So there were really two gas discounts that Russia was giving, neither of which really mattered since Ukraine was a complete deadbeat about paying for any of it.
So Ukraine owes Russia for the gas and it owes Russia for the portion of the loan it got in December, and it still owes the IMF for a loan it got in 2008, and with less legal certainty it owes for the portion of the Black Fleet lease that Russia pre-paid.
All of which will soon be transferred to the tab of the US taxpayers, thanks to the meddlesome neocons at the Obama State Dept. and the Republican pep squad in the US Senate.
Well, finally someone got it right.
The 2013 loan package wasn't signed off by either side.
The only discount active was the Black Sea Fleet lease discount.
You forgot the part where Russia owes Ukraine a naval base and some territory. If the deal is torn up.