New airline security screening procedures on US-bound flights begin this week. All incoming flights to the United States will undergo enhanced security screening procedures before takeoff. The new regulations will apply to both American citizens and foreigners.

Here is what we know so far:

The new rules will be imposed on American and international airlines, affecting all of the 2,100 flights from around the globe entering the U.S. on any given day.

The new orders surpass an earlier Trump administration ban which only targeted 10 Mideast cities and their airlines regarding laptops inside the cabins of some airliners.

Each carrier has viewed and interpreted the new rules in their own way. Exactly how they intend to enact the guidelines is not yet clear.

Five global, long-haul operators offered different descriptions of how the procedures would take place, ranging from a form travelers would fill out to being verbally questioned by an airline employee.

Some carriers have claimed their operations will remain unchanged, despite the new requirements.

The enhanced airline security measures affect all individuals, international passengers and U.S. citizens, traveling to the United States from a last point of departure at an international location, according to a spokesperson for the U.S. Transportation Security Administration.

“These new measures will impact all flights from airports that serve as last points of departure locations to the United States.”

The updated measures include “heightened screening of personal electronic devices” along with stricter security procedures around planes and in airport terminals, the spokesperson said.

Delta Air Lines reportedly said it is telling passengers traveling to the U.S. to arrive at the airport at least three hours before their flight and allow extra time to get through security. The new measures may pose longer waiting times for those traveling on domestic flights at some international airports, due to longer lines with check-in or baggage.