Republican Senator Bob Corker made a few controversial remarks about the President following a heated Twitter exchange with him on Sunday morning.

Senator Corker said that President Trump was treating his job like a reality show, a nod to Trump’s old television program “The Apprentice.”

According to Corker, Trump “…acts like he’s doing ‘The Apprentice’ or something,” emphasizing his concern for Trump not taking his presidential job seriously.

The senator also mentioned how concerned he was with the President’s actions, adding that he believes President Trump’s behavior could start us “on the path to World War III.”

Before Corker made his comments, Trump took to Twitter blasting the senator for the Iran Deal and more:

“Senator Bob Corker ‘begged’ me to endorse him for re-election in Tennessee. I said ‘NO’ and he dropped out and said could not win without my endorsement. He also wanted to be Secretary of State, and I said ‘NO THANKS.’ He is also responsible  for the horrendous Iran Deal!”

In response to this, Corker tweeted, “It’s a shame the White House has become an adult day care center. Somebody obviously missed their shift this morning.”

Corker’s support is crucial for Trump to pass tax reform. If accomplished, it will be the President’s best chance for a legislative landmark this year, according to NYT.