Transportation Security Administration officials expect more than 2.2 million to 2.3 million passengers to pass through airport security checkpoints around the country daily this summer.

"We're looking at a pretty busy summer travel season," particularly over holiday weekends including Memorial Day, Fourth of July and Labor Day, said TSA administrator David Pekoske during a conference call briefing with reporters.

On some days, there could be as many as 2.7 million passengers passing through airport checkpoints nationally, according to Pekoske.

Air travel is increasing at about 4 percent a year, he said. He said during the spring break travel period, "there were to the best of my knowledge no wait time issues through our entire system."

Pekoske advised travelers to follow TSA officers' instructions at the checkpoint, which could involve removing more items from carry-on bags and putting them into bins.

That includes electronics larger than a cell phone such as iPads. And it could include food.

TSA starting last year said its officers “may suggest passengers remove other select items, including food, from their carry-on bags. This is not required, but also helps X-ray operators get a clearer view of the contents of the bag and speeds up the screening process.”

Pekoske said by de-cluttering the X-ray image, “ultimately it should take less time” by reducing the need to re-screen bags.