U.S. Secretary of State Antony Blinken arrived in Kyiv on Tuesday on an unannounced visit to reaffirm America’s support for Ukraine, which is struggling in the face of ammunition shortages and increasingly intense Russian attacks. Blinken flew to Poland and took an overnight train to Kyiv, where he arrived on early Tuesday morning. The trip was kept secret from the public and was only announced when the diplomat had already arrived in the Ukrainian capital. Matthew Miller, a spokesman for the U.S. State Department, said Secretary Blinken would use the two-day trip to meet with Ukrainian Presid…