Trump has teased the possibility he may release a transcript of his phone call with Zelensky, a move that several Republicans have publicly pushed him to do.
On Saturday, Ukrainian Foreign Minister Vadym Prystaiko said he didn't think Trump pressured Zelensky during the phone call. Trump and Zelensky are set to meet face to face this week on the sidelines of the United Nations General Assembly session in New York.
Trump and his personal attorney Rudy Giuliani have engaged in a monthslong effort to have Ukraine probe the Bidens — an effort aided by the State Department.
It centers on the former vice president's 2016 call, widely backed by the international community, for Ukraine to crack down on corruption. That included a call to remove a Ukrainian prosecutor, Viktor Shokin, who was seen as ineffective and was later removed by the country's Parliament. One of the cases that Shokin was investigating involved Burisma Holdings, a natural gas company, whose board at the time included Biden's son.
Earlier this year, Bloomberg News, citing documents and an interview with a former Ukrainian official, reported the Burisma investigation had been dormant for more than a year by the time Biden called for the crackdown on corruption. The then-Ukrainian prosecutor general told the news agency he found no evidence of wrongdoing by Biden and his son. And PolitiFact reported it found no evidence to "support the idea that Joe Biden advocated with his son's interests in mind."