A British counter-terrorism expert says unspecified terror threats that have triggered heightened security at airports in Britain and Europe are a timely warning against complacency.
Reports from the United States suggest that Islamist terrorists with links to al Qaeda in Syria and Yemen are developing bombs undetectable by routine checks.
Richard Barrett, a former Director of Global Counter Terrorism Operations for Britain's MI6, told Radio New Zealand's Nine to Noon programme on Friday such alerts should give reassurance that the system is working.
"A threat is one thing, an actual attack's another. And of course so far as a terrorist is concerned, it's the threat that is important as the attack, because you want people to be reacting, you want people to be talking about them and you want people to feel afraid."
Mr Barrett said the extra security measures could deter potential terror attacks.
The Aviation Security Service said on Friday there has been no request for New Zealand to increase screening for passengers on direct flights to the US.
A spokesperson for the government service said New Zealand is considered a low-risk for terrorist attacks.
There is already screening in place for direct flights to the US, he said, including swabbing random passengers' socks, palms and belts for residue of explosives, and there is room to extend this if required, but it has not been requested.