By Sabine Siebold and John Irish BUCHAREST (Reuters) – NATO chief Jens Stoltenberg will call on allies to pledge more winter aid for Kyiv at a meeting on Tuesday and Wednesday, after Ukraine’s president told residents to brace for another week of cold and darkness due to Russian attacks on infrastructure. NATO foreign ministers meeting in Bucharest will focus on ramping up military assistance for Ukraine such as air defence systems and ammunition, even as diplomats acknowledge supply and capacity issues, but also discuss non-lethal aid as well. Part of this non-lethal aid – goods such as fuel,…