KIEV, Ukraine — Ukraine’s top prosecutor said on Friday that he would review several important cases previously handled by his predecessors, including a criminal case involving the owner of a natural gas company that employed a son of former Vice President Joseph R. Biden Jr.
The development came amid an impeachment inquiry against President Trump connected to a request he made to the Ukrainian president asking him to investigate Mr. Biden, a Democratic presidential candidate, and his son’s work in Ukraine.
It raises questions of whether Ukraine was, in effect, bowing to public and private pressure from the president of the United States, on which it has depended on for millions of dollars in aid.
The prosecutor general, Ruslan Ryaboshapka, said he intended to review 15 cases in all, and mentioned several high-profile investigations of wealthy Ukrainians, including the owner of the natural gas company, Burisma Holdings, where Mr. Biden’s son Hunter served on the board until earlier this year.