Ukraine says Russia has cut off all gas supplies to Kiev, in a major escalation of a dispute between the two nations. “Gas supplies to Ukraine have been reduced to zero,” Ukrainian Energy Minister Yuri Prodan said. Russia’s state-owned gas giant Gazprom said Ukraine had to pay upfront for its gas supplies, after Kiev failed to settle its huge debt. Gazprom had sought from Kiev $1.95bn (£1.15bn) – out of $4.5bn it says it is owed – by 06:00 GMT. The Russian firm said it would continue to supply gas to Europe. Russia-Ukraine ties remain tense since Moscow annexed Crimea in February. Kiev says Moscow backs separatists in the east of the country. Russia denies the charge. ‘Blackmail’ “Today, from 10:00 Moscow time, Gazprom, according to the existing contract, moved Naftogaz to prepayment for gas […]