Nebraska Sen. Ben Sasse sharply criticized President Trump on Sunday for attacking a federal judge who issued a ruling Friday that has prevented his administration from executing a ban on immigration from seven predominantly Muslim countries.

Trump had referred to U.S. District Court Judge James Robart as a "so-called" judge in a tweet on Saturday while calling his ruling "ridiculous" and predicting that it "will be overturned."

"I'll be honest, I don't understand languages like that. We don't have so-called judges. We don't have so-called senators. We don't have so-called presidents," Sasse said on ABC's "This Week."

"We have people from three different branches of government who take an oath to uphold and defend the Constitution and it's important that we do better civics education for our kids," he added. "So we don't have any so-called judges. We have real judges."

Sasse, an early critic of Trump during the election, has questioned the president's handling of a number of issues, including immigration and national security. However, the Nebraska Republican issued rare praise of Trump last week after he announced his Supreme Court pick.