By Pavel Polityuk and Natalia Zinets KYIV (Reuters) – Making the first official U.S. visit to Ukraine since Russia invaded two months ago, Washington’s top diplomat and its defense secretary pledged additional military aid, including advanced weapons, and a return of U.S. envoys to Kyiv. Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin met Ukrainian President Volodomyr Zelenskiy and other top officials in Kyiv late on Sunday, having travelled overland from Poland in a visit designed to show Western support. U.S. officials said the cabinet secretaries pledged new assistan…