Since the overthrow of the Russia-backed government of then President Viktor Yanukovych in February, the country has been rocked by disputes over the governance of regions including Crimea and parts of eastern Ukraine, a conflict which has drawn attention around the world. Ukraine has moved away from its historic alliance with Russia into closer ties with Europe, with an International Monetary Fund bailout replacing earlier Russian financial help and an association agreement made to trade with the European Union.
In recent weeks, pro-Russian separatists in several regions have captured key buildings and towns.
Russia has also hiked the (historically low) price it charges Ukraine for supplying gas, and called in its neighbor's debts over previous supply. On Tuesday, Interfax news agency quoted Russian Energy Minister Alexander Novak as saying the European Union had requested gas talks on Friday.