Airline passengers travelling to Britain from Turkey, Lebanon, Jordan, Egypt, Tunisia and Saudi Arabia are banned from taking most electronic goods on board in their carry-on luggage.
The restrictions, which apply to laptops, tablets, DVD players and phones over a certain size, follow a similar US ban affecting eight countries.
The US move was prompted by reports that militant groups want to smuggle explosive devices inside electronic gadgets, officials said.
The Department of Homeland Security said passengers travelling from nine airlines operating out of 10 airports could not bring devices such as tablets, portable DVD players, laptops and cameras into the main cabin that are larger than a mobile phone. Instead, such items must be in checked baggage.
The nine airlines affected by the US ban are Royal Jordanian, Egypt Air, Turkish Airlines, Saudi Arabian Airlines, Kuwait Airways, Royal Air Maroc, Qatar Airways, Emirates and Etihad Airways. The policy does not affect any American carriers because none fly directly to the United States from the airports affected, officials said.
The British measures affect six British carriers and eight overseas airlines.
Passengers from some of the busiest hubs in the Middle East, Turkey and North Africa will be affected.
The Turkish government has said the US ban is wrong and should be reversed.
But the Department of Homeland Security said extremists were seeking "innovative methods" to bring down jets.
Asked why the US ban differed from the UK, a spokesperson for Prime Minister Theresa May said: "We have each taken our own decisions."
Downing Street said measures followed talks on air security and were "necessary, effective and proportionate".
US officials said the decision had nothing to do with President Donald Trump's efforts to impose a travel ban on citizens of six majority-Muslim nations. A Department of Homeland Security spokesperson said the government "did not target specific nations. We relied upon evaluated intelligence to determine which airports were affected."
On 6 March, Mr Trump signed a revised executive order barring citizens from Iran, Libya, Syria, Somalia, Sudan and Yemen from traveling to the United States for 90 days. Two federal judges have halted parts of the ban although Mr Trump has vowed to appeal.
- BBC / Reuters