US border control agents have not been using the right software to verify e-passports for more than a decade, two US senators claim.
Oregon senator Ron Wyden and Missouri senator Claire McCaskill have asked US customs officials to start properly authenticating e-passports.
If data on smart chips cannot be checked, it is not possible to tell if it has been tampered with, they say.
Anti-forgery measures in e-passports have never been implemented.
The US was one of the first countries in the world to adopt e-passports, and travellers from countries on the visa-waiver list are now required to enter the country using e-passports, which speed up the time needed to process individuals in border control.