Remember all those thousands of passengers that airlines banned for not wearing face masks? Now the airlines want them back — or at least, most of them.

Officials with United Airlines and American Airlines said Thursday that they will lift the bans now that masks are optional on flights. United CEO Scott Kirby says many of those passengers promise to behave, and he believes them.

American Airlines official Nate Gatten says most people who were banned for refusing to wear a mask will be allowed back. But Gatten says those whose behavior escalated beyond a mask violation — to things including assault — will never be allowed back.

The airlines lifted their mask requirements after a federal judge ruled that a government-imposed mask mandate for public transit was unlawful.

However, some airlines warned that there may be cases where a mask is required.

"Please note face masks may still be required based on local ordinances, or when traveling to/from certain international locations based on country requirements," American Airlines said in a statement.

It wasn't just airlines that dropped their mask requirements on Monday, Amtrak also said masks are now optional for passengers and employees.