Ukrainian President Volodymyr Zelenskiy's chief of staff sent in a letter of resignation, after two months in his job, but Zelenskiy has not signed it, according to a statement on the presidential website on Friday.
Mystery has surrounded the status of Andriy Bogdan, the head of the presidential administration, since Thursday evening.
The local news agency Interfax
Ukraine had reported Bogdan's resignation but later retracted the story.