The origins of the story also trace back to Trump lawyer Rudy Giuliani, who has repeatedly pushed unfounded claims about Biden and his son, Hunter Biden.
Hunter Biden joined the board of the Ukrainian gas company Burisma in 2014, around the time his father, then U.S. vice president, was helping conduct the Obama administration's foreign policy with Ukraine.
The Biden campaign didn't address that issue on Wednesday and Hunter Biden's lawyer did not return an email seeking comment from the AP.
“We should view it as a Trump campaign product,” Jankowicz said.
Biden's campaign, meanwhile, pointed to the recent Republican-led Senate investigation that found no evidence of wrongdoing on Biden's part with regard to Ukraine.