(Reuters) – U.S. Secretary of State Antony Blinken and Defence Secretary Lloyd Austin were to visit Kyiv on Sunday to discuss Ukraine’s request for more powerful weapons after two months of combat with invading Russian forces. President Volodymyr Zelenskiy announced the visit. FIGHTING * Senior Ukrainian negotiator and presidential advisor Mykhailo Podolyak said Russian forces were continuously shelling Mariupol and urged Moscow to agree a “real Easter truce”. * Russia’s defence ministry said its high-precision missiles struck nine Ukrainian military targets overnight, including four arms depo…