Passengers flying to the US face tighter vetting and “enhanced screening” of large electronic devices, such as laptops and iPads

Travellers are being advised to allow additional time to clear check-in and security screening amid fears that the new controls could lead to delays at airports.

The tighter controls unveiled by homeland security secretary John Kelly will apply to the estimated 280 airports in 105 countries – offering flights to the US.

Countries that fail to meet standards set by Washington could see flights to the US suspended completely, the Daily Telegraph reported.

The US imposed a band on large electronic devices in aircraft cabins from ten mainly Muslim countries in March but plans to extend the ban to other countries has faced resistance.

As a result, Kelly has ordered all airports serving the US to tighten security, threatening strict sanctions on countries which fail to comply.

The new measures will be “seen and unseen”, the US Department of Homeland Security said.

“Those who choose not to co-operate or are slow to adopt these measures could be subject to other restrictions – including a ban on electronic devices on their airplanes, or even a suspension of their flights to the United States,” Kelly said.

“We expect all airlines will work with us to keep their aircraft, their crew, and their passengers safe.

“I have spent months engaging with our closest allies and foreign partners on this issue, and many of them have expressed strong support for this effort.

“While the actions we are announcing today will improve the security of US-bound flights, I am hopeful other nations will follow suit.

“Unless we all raise our security standards, terrorists – who see commercial aviation as the greatest takedown – will find and attack the weakest link.”

Kelly added: “Our enemies are constantly working to find new methods for disguising explosives, recruiting insiders, and hijacking aircraft.

“We cannot play international whack-a-mole with each new threat. Instead we must put new measures in place across the board.”

Measures taken at airports across the globe will vary.

“The safety and security of the travelling public is our top priority, and the UK has some of the most robust aviation security measures in the world,” a Department for Transport spokesman said.

“It is for the US to determine its own security measures based on its own assessments, just as we do ourselves.

“We work closely with all our international partners to keep aviation security under constant review, but for obvious reasons we do not comment on specifics.”

A Heathrow spokesman added: “Alongside our airline partners, we will work to ensure passenger journeys through Heathrow are as smooth as possible and will provide advice to passengers in due course.”

More than four million Britons travel to the US each year.