They said it was on again, then it was off. First there was a deal, then there wasn’t. Now today, after saying Russian gas deliveries to Europe had restarted, Gazprom in Moscow said Ukraine had blocked the transit. Minutes later, Kiev admitted the report.And added to the chaos over Russia’s gas dispute with Ukraine, reports say a Gazprom head today pointed the finger at Washington as being behind Ukraine’s action. Earlier, the European Union praised the announcement of gas deliveries to the bloc being resumed, after numerous on-again-off-again deals. That praise now seems to have been premature. If and when the gas comes back on, experts are warning it will take up to 36 hours for supplies to be fully restored. At the root of this crisis, which observers say has badly damaged the reputation of Russia and Ukraine as reliable gas providers, is a dispute over prices and claims of unpaid bills. The European Union got involved in the row when numerous countries in the bloc began to be affected a week ago. Russia halted deliveries at a time of freezing temperatures across the continent, and accused Ukraine of siphoning off gas destined for Europe. Kiev denies the claims.