In spat over Ukraine, Putin tells U.S. not to read others' letters

MOSCOW (Reuters) - Russian President Vladimir Putin responded acidly to U.S. comments about a proposal he sent to European leaders seeking talks about Ukraine's gas debt and supplies, saying "it is not good to read other people's letters". In a letter to 18 European leaders on Thursday, Putin said Russian gas supplies to Europe could be disrupted if Moscow cuts the flow to Ukraine over unpaid bills, drawing a U.S. accusation that Russia is using energy as a 'tool of coercion'. (Writing by Steve Gutterman)