The Department of Justice has rules against taking investigative steps that would have an affect on any election, and Barr's decision to keep the investigations under wraps might have been in order to satisfy that policy.
On Friday the president reacted negatively to the report via his social media account.
"Now it turns out that my phone call to the President of Ukraine, which many, including me, have called 'perfect', was even better than that," tweeted Trump.
Now it turns out that my phone call to the President of Ukraine, which many, including me, have called “perfect”, w… https://t.co/rbk7zyMLyQ— Donald J. Trump (@Donald J. Trump) 1607691147.0
"I predicted Biden corruption, said to call the A.G. [Bill Barr], who perhaps knew of the corruption during the impeachment hoax?" he added.
The president was referring to a conversation he had with Ukrainian President Zelensky where he asked him to look into charges of corruption against former Vice President Joe Biden. Democrats impeached the president partly over the call because they said it was an abuse of power.
While accusations of criminal activity by Hunter Biden were tossed around before the election by allies of the president, the existence of a federal investigation was revealed on Wednesday.
"I learned yesterday for the first time that the US Attorney's Office in Delaware advised my legal counsel, also yesterday, that they are investigating my tax affairs," said Hunter Biden in a statement put out by the Biden Harris transition team.
"I take this matter very seriously, but I am confident that a professional and objective review of these matters will demonstrate that I handled my affairs legally and appropriately, including with the benefit of professional tax advisors," he added.
A later report said that the probe was much more expansive than his "tax affairs," and could include accusations of money laundering and illegal conduct with foreign countries.
Here's more about the rift between Trump and Barr:
Trump rips Barr over report he knew about Hunter Biden probewww.youtube.com