Sex offenders who have committed sex crimes against minors will have their crimes identified on their passports.
The criminals will have their original passports revoked, under the new US law.
If they wish to travel outside the US they will be required to apply for new travel documents which identify them to passport officials.
Those applying for first time passport will be issued with one containing the identifier, too.
The altered passport will feature a printed notice inside the back cover of the book.
It will read: “The bearer was convicted of a sex offence against a minor, and is a covered sex offender pursuant to (U.S. law).”
The change was announced in a statement on the US travel.state.gov website.
It also means child sex criminals will not be allowed to apply for passport cards, an identity card used for domestic flights within the US.
The change affecting passports came into effect on October 31 2017.
It comes after last year’s “International Megan’s Law”, which aims to tackle child exploitation and child sex tourism.
The US law is named after Megan Kanka, a seven year old girl who was murdered by a convicted child sex offender in New Jersey in 1994.
The case prompted led to the establishment of a number of state sex offender registers.
As a result of the new passport initiative, the State Department will be able to track offenders more easily.
It will also make sure the border officials at the countries they enter are immediately aware of their crime.
Some Twitter users have called for harsher measures like barring child sex offenders from entering countries, or not allowing them to have passports.
One user wrote: “Why would the government give you a passport if you are a convicted child sex offender?”.
