Travellers arriving bleary eyed to crowded U.S. airports won't have to fill out onerous customs forms by the end of 2016, the government said Friday, part of a drive to curb lengthy waits.

Announcing measures "to improve the arrivals process at all airports," the White House said it was scrapping "6059b customs declaration forms" which ask, among other things, whether travellers are bringing soil or snails into the country.

"The safety and security of this country will always come first, but we can and must also ensure that the travel experience continues to be welcoming, friendly, and efficient," the White House said.

Action plans for the 17 busiest airports will be introduced, as well as automated passport control kiosks and the ability to submit passport information via smartphone.

Millions of travellers visit the United States each year, spending an estimated $222 billion last year alone.