WASHINGTON — A Homeland Security official said Thursday that if Secretary John Kelly expands a ban on carrying large electronic devices onboard flights to the U.S., it might also apply to overseas flights that originate in the U.S.

“As we’ve said all along, the Secretary’s view continues to evolve,” spokesman Dave Lapan said. “At this point, we don’t know what it will look like.”

Asked Sunday on Fox News Sunday whether he might ban the devices on all international flights, both into and out of the U.S., Kelly replied, “I might.”

A global airline industry group said Thursday that a limited form of the ban already in place appears to have reduced travel on the affected routes.

While worldwide air travel was up in March, it fell by about three percent from what it was a year before on routes to the U.S. flown by Middle Eastern airlines, according to the International Air Transport Association.

The Department of Homeland Security ordered airlines operating from 10 Middle Eastern and African airports to prevent passengers from carrying onboard electronic device larger than a cell phone, on direct flights to the United States. The devices must be stored in a passenger’s checked baggage.

Homeland Security officials have been considering expanding the restriction to U.S.-bound flights from Europe, but they stress that no decision has yet been made.

Alexandre de Juniac, the airline group’s director general and CEO, said extending the ban to include flights from Europe would produce “a $1.4 billion hit on productivity,” because passengers would not be able to use laptop computers to work in the air.

Lapan said Tuesday’s fire aboard a Jet Blue flight caused by a lithium-ion battery did not change the government’s thinking about expanding the restriction on electronic devices.

The flight, from New York to San Francisco, was forced to land in Michigan, and opponents of expanding the restriction have said that forcing more laptops and other devices into a plane’s cargo would present a safety hazard.

“We are well aware of the potential danger of lithium-ion batteries, but our concern is aviation security,” Lapan said. A large number of on-board fires, he said, have been caused by smart phones and e-cigarettes, not laptops.

Despite repeated concerns expressed by airlines, airports and European officials, Lapan said expanding the restriction “is still on the table.”

He acknowledged that imposing the restriction on dozens of European airports responsible for hundreds of flights to the US would be complex and difficult.

Recent discussions with European authorities and the airlines have made it clear that such a move “would be more complicated than originally thought. Some of the specifics are more clear,” he said.