The U.S. government is imposing broad new demands for increased airport security on all flights to America from other countries in an attempt to combat the threat of terrorists hiding bombs in laptops and other electronic devices.
DHS officials said that the changes will be "seen and unseen" and could include additional screening for travelers and their laptops, e-readers and tablets as well as the expansion of Preclearance, a program in which U.S. Customer and Border Protection officers conduct screening at worldwide airports.
"We send a clear message that inaction is not an option", DHS Secretary John Kelly said in Washington.
If they don't, they could face the possibility of a total electronics ban for planes.
Kelly said he planned a "step by step" security enhancement plan that included short, medium-term and longer-term improvements that would take at least a year to implement fully.
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.
Kelly said some measures will be noticeable by passengers while others will be unseen.
Now, however, the USA government will seek to apply new rules to flights regardless of where they originate.
Since March, passengers on flights to the US from certain mostly Middle Eastern countries, have been prohibited from bringing electronic devices larger than a cellphone on board with them.
Airline officials said they will have to bear the brunt of expanded screening costs.
Such a laptop ban has been in place at 10 airports in the Middle East and Africa. "They still see aviation as the crown-jewel target". The official also described the measures as "intensive".
The U.S. does not have jurisdiction over foreign airports, but has authority over airlines that have direct flights into the country.
In recent weeks, Kelly and his aides have huddled with their counterparts overseas, as well as with representative of major airlines, to discuss whether to expand the ban around the globe.
He said new computer tomography or "CT" scanners being tested in Boston and Phoenix could help address long-term screening issues.
The enhanced protocols may be a relief for the airline industry and other stakeholders who pushed back against the potential laptop ban expansion, which they feared would create chaos and hurt their business.
Robert Mann, analyst at R.W. Mann & Co, said if US officials had insisted on a expanded laptop ban, it could harm business travel.