After Zelenskyy, 43-year-old Kuleba was the best-known face of Ukraine overseas, meeting leaders around the world and lobbying for military and political support in fluent English.<BR><BR> More resignations and appointments are expected over the coming days after five ministers stepped down on Tuesday, in what a senior Zelenskyy ally cast as the start of a government "reset" ahead of the cold autumn and winter seasons.<BR><BR> Kuleba's resignation letter was posted on Facebook by the parliament speaker, Ruslan Stefanchuk.<BR><BR> Zelenskyy has said changes to the government are necessary to achieve the results required by Ukraine.<BR><BR> "Autumn will be extremely important for Ukraine. And our state institutions should be configured so that Ukraine achieves all the results that we need - for all of us," he said on Tuesday.