Tallahassee mayor and Florida gubernatorial candidate Andrew Gillum said Monday that President Trump should "grow up."

Earlier in the day, Trump directed a tweet at Gillum, calling him a "thief" and expressing his support for Rep. Ron DeSantis, R-Fla., for governor.

Gillum told the Guardian's Sabrina Siddiqui that the president "hasn't learned his lesson," pointing to recent events which critics are tying to Trump's bellicose rhetoric.

"I think the president should grow up," Gillum said. "I think, again, he hasn't learned his lesson. These kinds of attacks [are] baseless, but mostly unfortunate, because I think this is the kind of stuff that gives rise to people."

Pointing to a Florida man who is suspected of sending more than a dozen mail bombs to prominent Democratic figures, Gillum added, "In this day where we're seeing such dangerous rhetoric turn into political violence, I think the president should demonstrate more maturity and restraint."

In his tweet, Trump called attention to a federal corruption inquiry in Tallahassee from which documents show Gillum may have improperly received gifts.

"In Florida there is a choice between a Harvard/Yale educated man named @RonDeSantisFL who has been a great Congressman and will be a great Governor - and a Dem who is a thief and who is Mayor of poorly run Tallahassee, said to be one of the most corrupt cities in the Country!" Trump said.

Gillum shot back with a tweet of his own, saying, "On Twitter there is a choice between having the courage to @ the person you are trash talking, or not. @realDonaldTrump is howling because he's weak. Florida, go vote today."

Gillum is facing off against DeSantis, who also faces questions about taxpayer money use, in the race for Florida governor. He leads in the latest RealClearPolitics polling average by 3.2 percentage points.