In his interview with "Fox News Sunday", Kelly acknowledged that the US will rely on "new technologies down the road" to improve the screening of electronics. Electronic devices bigger than smartphones have to be checked in on those flights.
This follows a ban imposed in March on all electronic devices larger than a smartphone in aircraft cabins on flights.
Just three days after US president Donald Trump's visit to Brussels, the USA homeland security secretary John Kelly has said he may ban laptop computers and large devices in the cabins of all worldwide flights.
"It is a real sophisticated threat, and I will reserve that decision until we see where it is going", Mr Kelly said of when a final ruling might come and what it might be.
USA officials have said that initial ban was not based on any specific threat but on longstanding concerns about extremists targeting jetliners. The UK has also implemented a similar ban on flights coming from six specific countries.
The measure applies to nonstop US-bound flights from 10 worldwide airports in 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.
American officials lately had a meeting with Europe's leaders to negotiate expanding the travel ban to flights between the U.S. and EU.
No official ban has been placed as of this writing. Recently, Politico reported that U.S. airlines are still planning for an "imminent" extension of the prohibition to Europe and maybe other regions.
According to the International Air Transport Association, around 4,300 international departures and arrivals take place in the United States on a daily basis, transporting about 560,000 passengers.
"There΄s a real threat - numerous threats against aviation", Kelly told the Fox News less than a week after the bombing at an Ariane Grande concert in Manchester in the United Kingdom.
Foreign visitors spent $246 billion in the United States a year ago, supporting 8.6 million employees in the American tourism industry. Reportedly, four major screening machines companies are working on sophisticated scanners to identify explosives.