By Philip Pullella VALLETTA (Reuters) -Pope Francis said on Saturday he was considering a trip to Kyiv and implicitly criticised Russian President Vladimir Putin over the invasion of Ukraine, saying a “potentate” was fomenting conflict for nationalist interests. Francis made the comments, first to reporters on the plane taking him to Malta for a two-day visit, and then in a hard-hitting speech in the island’s presidential palace that left little doubt who he was referring to. “From the east of Europe, from the land of the sunrise, the dark shadows of war have now spread. We had thought that in…