Washington (AFP) – The White House said Wednesday it was increasingly concerned over Moscow’s talk of using a nuclear weapon in Ukraine, after a media report said top Russian military officials had discussed how and when to use such a weapon. “We have grown increasingly concerned about the potential as these months have gone on,” said White House national security spokesman John Kirby. Kirby did not confirm a New York Times report that said high-level Russian military officials recently discussed when and how they might use tactical nuclear weapons on the battlefield. The report, which cited…