Ukraine's new pro-Western leader enters a defining week today seeking to head off a Russian gas cut and secure US President Barack Obama's backing with his country threatened by civil war.
Confectionery tycoon Petro Poroshenko will also attempt to arrange the first meeting with Russian President Vladimir Putin since the February ouster of a pro-Kremlin regime in Kiev sparked the worst East-West crisis since the Cold War.
And it ends Saturday with the 48-year-old sworn in as the fifth president of Ukraine after a convincing first-round May 25 election win handed him a mandate to resolve a separatist insurgency threatening the very survival of the ex-Soviet state.
"These meetings will be crucial," said Kiev-based political analyst Volodymyr Fesenko.
"They will help establish direct relations and introduce Petro Poroshenko to world leaders -- first and foremost, Barack Obama."
Ukraine's third "gas war" with Russia in less than a decade erupted when Moscow -- stunned by the sudden ouster of an ally who had just rejected an EU alliance that the Kremlin greatly feared -- nearly doubled the price it charges its neighbour for the fuel.
Kiev accused Moscow of "economic aggression" and refused to cover a bill that Russia puts at USD 5.17 billion.
Russian gas transits through Ukraine supply about 15 percent of European needs and a top EU envoy is now urgently seeking a compromise that could save 18 member states from seeing supply cuts go into effect Wednesday.
A final round of talks has been set for Monday in Brussels after Ukraine's Naftogaz state energy firm – bowing to both EU and Kremlin pressure -- transferred a $786 million payment to its Russian counterpart Gazprom to keep the talks alive.
Gazprom now says it is willing to discuss a lower price and analysts believe that a compromise is in sight.
"Our view is that Gazprom and Naftogaz will eventually reach a compromise," Moscow's VTB Capital investment bank said in a research note.