Robert J. O'Neill, a member of the SEAL Team Six member that killed Osama bin Laden more than a decade ago, posted a tweet on Sunday saying that while the "Taliban controls Afghanistan," he has been placed on a "no-fly list."

"20 years after 9/11. The Taliban controls Afghanistan. The Guy who killed bin Laden is on a no-fly list," O'Neill wrote on September 12, the day after the 20 year anniversary of the 9/11 attacks on the US.

Back in August, O'Neill said he was banned from Delta Airlines for not wearing a mask as required by the airline for travel.

The ban reportedly came after he posted a photo to Twitter of himself with no mask, as a nearby passenger and passing flight attendant are seen wearing one. The photo was captioned "I'm not a p*ssy."

O'Neill tweeted a few days later that he was banned from Delta for that photo.

In August, a spokesperson for Delta Airlines confirmed the ban to The Daily Wire, saying "Part of every customer's commitment prior to traveling on Delta is the requirement to acknowledge our updated travel policies, which includes wearing a mask."

"Delta customers and employees are required to wear a face mask, or appropriate cloth face covering over their nose and mouth throughout their travel, aligning with best practice guidelines from the CDC," Delta states on their website.

Following O'Neill's post, many on Twitter took to criticizing his actions, including Dan Saltzstein, a New York Times deputy editor.

In a now deleted tweet, he said "I don't know this guy but: counterpoint, you might just be because you're not willing to sacrifice and be a little uncomfortable for your fellow humans (including that marine behind you)!" The Daily Wire reported.

Saltzstein deleted the tweet, posting instead a message that both honored and slammed O'Neill.

"I deleted a previous version of this tweet because I broke my own rule about name-calling. So let me try again: I honor O'Neill for his sacrifices to his country and his heroism. It's sad that he can't extend the same for the safety of his fellow passengers," he wrote.

O'Neill has been a huge opponent to COVID-19 mandates in recent months, slamming everything from vaccines to the need to to show "papers" to conduct daily life.