The US has announced "enhanced security measures" for all flights travelling to the US.
The new rules will apply to flights to the US from 280 "last-point-of-departure" airports in 105 countries.
New measures include increased screening of electronic devices, 'enhanced' passenger screening, and increased security protocols around planes.
Officials say the new measures will be implemented in phases over the coming weeks and months.
Announcing the measures, US Homeland Security secretary John Kelly stopped short of a wider ban on electronic devices or 'laptop ban' - but warned airports who do not cooperate could see such measures imposed.
Mr Kelly argued: "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.
"Today is just the starting point. We are taking prudent steps to make aircraft more secure, to reduce insider threats, and to identify suspicious passengers."
He added that countries "cannot play international whack-a-mole with each new threat", and insisted "inaction is not an option".
Mr Kelly also called for more airports to introduce preclearance facilities, which are already in place in Dublin.
The US has significantly increased security measures in recent months, including a controversial 'electronics ban' on flights from a number of major airports in the Middle East.