The Homeland Security Department is demanding that airlines around the world step up security measures for international flights bound for the United States or face the possibility of a total electronics ban for planes.
Compliance with the new rules could lead to the lifting of a ban on laptops and other large electronics already in place for airlines flying to the United States from 10 airports in the Middle East and Africa. It could also stave off a much-discussed expansion of the ban to flights from Europe.
Homeland Security Secretary John Kelly announced the rollout of the new rules Wednesday.
The changes will be phased in over time and include enhanced passenger vetting, explosives detection and efforts to root out insider threats to airlines.
"Security is my No. 1 concern," Kelly said during a speech at the Center for a New American Security. "Our enemies are adaptive and we have to adapt as well."
Kelly said the changes will be "seen and unseen" and will be phased in over the coming weeks and months.
He said airlines that don't comply or are slow to enforce the new standards could be forced to bar large electronics in both carry-on and checked luggage. They could also lose permission to fly into the U.S. He said he's confident that airlines will cooperate.
The current ban, with affects only foreign carriers flying to the U.S. from 10 cities, allows passengers to travel with larger electronics packed in checked baggage.
The new rules will apply to roughly 180 foreign and U.S.-based airlines, flying from 280 cities in 105 countries, according to Homeland Security. About 2,000 international flights land in the United States daily.
The original laptop and electronics ban has been in place since March amid concerns about an undisclosed threat described only as sophisticated and ongoing. That ban applied to nonstop flights to the United States from Amman, Jordan; Kuwait City, Kuwait; Cairo; Istanbul; Jeddah and Riyadh, Saudi Arabia; Casablanca, Morocco; Doha, Qatar; and Dubai and Abu Dhabi in the United Arab Emirates. The roughly 50 affected flights are on foreign airlines.
The government had considered expanding the laptop ban to include some European airports, though in recent public comments Kelly had suggested the government was looking at alternatives.
The changes comes after the Transportation Security Administration said this month that it is testing computed-tomography, or CT, scanning at one checkpoint at Phoenix Sky Harbor International Airport.
The technology is already used for screening checked luggage, but the cost and larger size of the CT scanners has held back their use for carry-on bags. TSA had expected to begin testing CT scanners for carry-on luggage by the end of 2016.
CT scanners create a 3-D image that can be rotated to give screeners a better look. Suspicious bags can be pulled aside and opened by screeners.
American Airlines, which is participating in the test, said the technology could let passengers leave laptops, liquids and aerosols in their carry-on bags, speeding up the trip through the airport.
The test comes as U.S. officials scramble to deal with potential new threats, including reports that terrorists are developing bombs that can be disguised as laptop batteries.
The ban on laptops in the cabin is based on the belief that a bomb in the cargo hold would need to be bigger than one in the cabin, and capable of remote detonation. Checked luggage already goes through computed-tomography screening while carry-on bags don't.
AP Diplomatic Writer Matthew Lee contributed to this report.