John Bacon

USA TODAY

Homeland Security officials and their European Union counterparts exchanged security information Wednesday in Brussels as U.S. officials pressed their plan to ban laptops and tablets from the cabins of trans-Atlantic flights amid warnings of a resulting "economic tsunami."

"Participants provided insight into existing aviation security standards and detection capabilities as well as recent security enhancements ... related to large electronic devices placed in checked baggage," DHS and the European Commission said in a joint statement.

The participants "reaffirmed their commitment to continue working closely together" and will meet again in Washington next week, the statement said.

The controversial U.S. plan would expand a ban established in March for in-flight laptops and other large electronics for U.S.-bound flights from 10 airports in eight countries in the Middle East and Africa. The expansion involves routes carrying up to 65 million people annually on more than 400 daily flights, DHS says.

DHS spokesman Dave Lapan said this week that the plan had not been affected by news that President Trump shared with Russian officials classified information relating to security threats, possibly involving laptops on planes. EU officials say they had not been briefed on the threat, the Associated Press reported.

Lapan said DHS Secretary John Kelly had not made a final decision on the ban, which has drawn fire from travel associations and even British airline pilots.

"The ripple effects of this could create an economic tsunami of the likes of which terrorists are dreaming of but instead it would be at the hand of government directive," Kevin Mitchell, chairman of the U.S.-based Business Travel Coalition, wrote in a letter to EU Council Chairwoman Violeta Bulc.

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​The International Air Transport Association, which represents more than 250 airlines in more than 100 countries, estimated the ban would cost more than $1 billion annually in lost time to passengers. The global consulting firm ICF estimated that 30% of the nearly 100,000 passengers who fly from Europe to the U.S. every day are business travelers who will be affected by a ban and almost 1 million hours of productivity would be lost per day.

Mitchell said the loss of hours of productivity working during a flight is just a small part of the problem. Most organizations won't allow employees to check laptops for security reasons, meaning U.S. travelers headed to Europe on business could find themselves without the vital tool for a week or more.

"That for most business travelers would be an absolute no-go, deal breaker," Mitchell wrote.

The U.S. airlines facing the biggest hit from any sharp decline in trans-Atlantic flights would be Delta, United and American.

With the extension of the ban still only speculation, U.S. carriers were mum Wednesday on details about how they might handle such a change.

United spokeswoman Erin Benson said the Chicago-based airline continues to monitor the situation.

“We are actively preparing contingency plans to support our customers and employees in the event we need to make any policy or procedure changes to comply with new government security directives,” she said in a statement to USA TODAY. “In the meantime, we continue to follow all existing policies.”

Officials at the USA’s two other big airlines that fly to Europe — American and Delta — declined to discuss what they might do should an electronics ban be extended to include flights from Europe, though they each said they’d comply with any new regulations that are ultimately enacted.

U.S. security officials said in March that the measure was adopted in response to two events: a bomb in a soda can suspected of destroying a Russian Metrojet above Egypt in October 2015 and a laptop suspected of blowing a hole in the side of a Daallo Airlines flight in Somalia in February 2016.

Checked baggage poses less of a threat because a bomb would need a sophisticated timer, says Jeffrey Price, who writes about aviation security as a professor at Metropolitan State University in Denver. Additionally, cargo luggage generally faces more stringent security checks than carry-ons, and a bomb in cargo would need to be more powerful than a bomb in the cabin, experts say.

The British Airline Pilots’ Association dissent was based on safety, however. The pilots issued a statement saying the risk arising from storing electronic devices in the hold where they may catch fire without being noticed could be greater than the security risk of having them in the cabin.

"Lithium battery fires, unless caught early, can spread quickly," the statement said. “If these devices are kept in the hold, the risk is that if a fire occurs the results can be catastrophic; indeed, there have been two crashes where lithium batteries have been cited in the accident reports."

Contributing: Kevin Johnson, Benjamin Mutzabaugh, Bart Jansen