Often dubbed "the world's greatest deliberative body," the U.S. Senate often functions like a high school, and Florida Sen. Marco Rubio is the kid who does not show up for class, GOP presidential hopeful Chris Christie said on Jan. 11.

The New Jersey governor's remarks were his latest attack on Rubio, whom Christie seems to perceive as one of his main rivals in the critical early primary races set to begin next month. Highlighting his own executive experience, Christie suggested that the Floridian's service in the Senate did not qualify him to serve as president, according to Politico.

"I say, Joe, the United States Senate's like school," the governor told MSNBC's "Morning Joe." "They tell you where to go, where to sit, then they tell you what you're going to talk about that day."

Rubio was frequently absent from Senate sessions in order to further his White House bid, Christie added.

"The truant officer is out looking for him," he said, as he highlighted Rubio's absence on the day of the spending bill vote last month. "That would be like me this week not showing up for the State of the State."

In recent weeks, Christie has increasingly targeted Rubio, singling out the senator in a campaign ad that warned that Republicans risk helping elect Democratic front-runner Hillary Clinton if they do not unite behind a candidate, NJ.com noted. Like Barack Obama in 2008, Rubio is a first-term senator and lacks the necessary experience to serve in the White House, the commercial suggested.

At a Jan. 5 campaign event in New Hampshire, where the nation's first primaries will take place, the New Jersey governor once again hammered Rubio over his attendance record in Congress.

"You go into the legislature, they schedule when you're supposed to be there, they tell you where to sit and then they say 'yes' or 'no,' say 'yes' or 'no,'" Christie said. "Senator Rubio can't even seem to get that done."