"I think it's a very sad day for our country. He worked for me for a very short period of time, but you know what, he happens to be a very good person. And I think it's very sad what they've done to Paul Manafort," Trump told reporters.
Manafort joined Trump's campaign in March of 2016 and served as chairman from May to August, 2016.
This is the second day of jury deliberations in Manafort's trial.
Manafort pleaded not guilty to tax evasion and bank fraud charges based on allegations that he hid income from the US Internal Revenue Service that was earned working for a Ukrainian political party.
In early August, Donald Trump said that he didn't know who had been treated worse, mafia boss Al Capone or his former campaign chairman. Trump also emphasized that Manafort had worked for him only for a short period of time.