Russia 's gas monopoly Gazprom accused Ukraine of cutting supplies . Gazprom cuts off gas supplies to Ukraine on New Year 's Eve . Company says Ukraine owes it about $ 2 billion for past natural gas sales . Gas supplies to other European customers may be affected .
Russia 's energy monopoly Gazprom accused Ukraine of siphoning supplies . Gazprom cuts off gas supplies to Ukraine on New Year 's Day . Company says Ukraine owes it about $ 2 billion for past natural gas deliveries . Fears supplies to other European customers will be affected .