Putin issued the ultimatum in a letter sent to heads of state in 18 European countries on Thursday, indicating Russia will use supplies from state-owned Gazprom as an economic weapon in the ongoing stand-off with the West over its annexation of the Crimea peninsula from Ukraine.
It comes after Russia removed a gas price discount on supplies to Ukraine to step up pressure on the Kiev government, which this week also failed to meet a repayment deadline on a $2.2
