The EU has turned up the heat on Russia and Ukraine over their worsening gas row which has threatened to disrupt supplies to many member states.As Moscow and Kiev trade accusations over bills and prices, the bloc has demanded that they resolve their differences and restore flow by the end of the week. Russia’s Gazprom said a delegation of officials would be travelling to Brussels tomorrow for talks with Commission officials, while the head of Ukraine’s state energy firm has said he plans to fly to Moscow tomorrow. There is growing pressure from within the bloc for a united response to the crisis. EU gas industry experts are due to discuss the situation in Brussels later this week. The Czech Republic, which holds the rotating presidency, says it is considering calling an emergency EU-Russia-Ukraine summit if the row is not settled.