LONDON (Reuters) -Russia’s foreign spy chief accused the United States and Poland on Thursday of plotting to gain a sphere of influence in Ukraine, a claim denied by Warsaw as disinformation aimed at sowing distrust among Kyiv’s supporters. Sergei Naryshkin, the chief of Russia’s Foreign Intelligence Service (SVR), cited unpublished intelligence that he said showed the United States and Poland, NATO allies, were plotting to restore Polish control over part of western Ukraine. “According to the intelligence received by Russia’s Foreign Intelligence Service, Washington and Warsaw are working on …