The now-famous July 25 call between President Donald Trump and Ukranian President Volodymyr Zelensky only occurred because Zelensky agreed to speak about former Vice President Joe Biden and his son Hunter.

According to an ABC News report, an adviser to Zelensky said that it was very clear.

"It was clear that Trump will only have communications if they will discuss the Biden case. This issue was raised many times. I know that Ukrainian officials understood," said Serhiy Leshchenko.

According to notes about the call that the White House released, Trump asked Zelensky for a "favor" to look into the Bidens.

"I would like you to do us a favor," Trump said to Zelensky. "I would like you to find out what happened with this whole situation in Ukraine ... There's a lot of talk about Biden's son, that Biden stopped the prosecution and a lot of people want to find out about that. So whatever you can do with the attorney general would be great. Biden went around bragging that he stopped the prosecution so if you can look into it ... it sounds horrible to me."

Read the full report at ABC News.