Delta Airlines passenger aircrafts are seen on the tarmac of John F. Kennedy International Airpot in New York,on December 24, 2021. - Over 2,000 flights have been cancelled and thousands delayed around the world as the highly infectious Omicron variant disrupts holiday travel. (Photo by Yuki IWAMURA / AFP) (Photo by YUKI IWAMURA/AFP via Getty Images)
CNN  — 

Delta Air Lines CEO Ed Bastian sent a letter to US Attorney General Merrick Garland last week reiterating his call for the Justice Department to prosecute unruly passengers and place them on a no-fly list.

A short response came on Tuesday.

“The Department of Justice is continuing to prioritize the investigations and prosecutions of those who engage in criminal behavior that threatens the safety of passengers, flight crews, and flight attendants,” said Joshua Stueve, department spokesman, in a statement.

“We are fully committed to holding accountable those who violate federal law. We will be referring Delta’s letter to appropriate departments.”

Bastian had called for a no-fly list in 2021 and repeated his call for urgent action on Friday, February 4.

“In addition to the welcome increase in enforcement and prosecutions, we are requesting you support our efforts with respect to the much-needed step of putting any person convicted of an on-board disruption on a national, comprehensive, unruly passenger‘“no-fly’ list that would bar that person from traveling on any commercial air carrier,” Bastian wrote to Garland, according to a copy of the letter reviewed by CNN.

“This action will help prevent future incidents and serve as a strong symbol of the consequences of not complying with crew member instructions on commercial aircraft,” Bastian said in the letter.

The letter was first reported by Reuters.

Bastian first called for a no-fly list in September in a memo to employees first reported by CNN.

President Joe Biden said in October that he has instructed the Justice Department to address rising violence on airplanes as some passengers resistant to mask requirements have threatened airline staff.

Transportation Secretary Pete Buttigieg said in late October that a federal no-fly list for violent airplane passengers “should be on the table.” The existing federal no-fly list is used to prevent terrorism.

“It is completely unacceptable to mistreat, abuse or even disrespect flight crews,” Buttigieg told CNN’s Dana Bash.

Delta kicked two unruly passengers off Flight 1582 from Fort Lauderdale to Atlanta on Tuesday.

“Delta has zero tolerance for unruly behavior at our airports and on our flights as nothing is more important than the safety of our customers and flight crews,” the airline said in a statement related to the incident.

2021 was a very bad year for bad behavior

Last year was the worst on record for unruly airplane passenger behavior in the United States, according to Federal Aviation Administration data.

A whopping 5,981 reports of unruly passengers were logged by the FAA as of December 31. Of those, 4,290 – nearly 72% - were mask-related incidents.

It’s been a little more than a year since the FAA announced a “zero tolerance” policy for unruly passenger behavior that skips warnings or counseling and goes directly to penalties, which can include heavy fines and jail time.

The policy, spurred by incidents tied to masks and violence at the US Capitol, was originally set to expire at the end of March 2021. It was extended at least until the federal mask mandate is lifted.

As of February 1, there have been 323 reports of unruly passenger behavior so far this year, according to FAA tracking. Of those, 205 were mask-related incidents. Seventy-three investigations have been initiated, with 26 enforcement action cases initiated so far this year.

The unruly passenger incident rate has dropped about 50% since record highs in early 2021, the FAA notes on the page where it tracks incidents, “but there remains more work to do.”

CNN’s Evan Pérez contributed to this article.