Terror fears prompt tighter screening of travellers allowed into US visa-free
Fears over Western jihadis fighting in Middle East behind requirement to provide additional information before being allowed aboard flights
The United States has imposed tighter screening measures on travellers from allied countries - mostly European but including Australia, New Zealand and some in East Asia - amid concern over the rising number of Islamist militants who have fought in Syria and hold Western passports.
The steps, introduced on Monday by the Department of Homeland Security, are aimed at 38 states and terriorites whose citizens are exempted from obtaining visas before entering the US. Travellers from Singapore, Japan, South Korea and Taiwan are among those affected.
The rules will require millions of travellers to provide more detailed information to US authorities before boarding their flight.
For the first time, US officials said, such travellers will be required to disclose whether they hold passports from multiple countries, or have previously used alternate names or aliases.
Homeland Security Secretary Jeh Johnson said the changes were needed "to learn more about travellers from countries from whom we do not require a visa". He said the requirements "will not hinder lawful trade and travel".
US officials said the changes were driven by concern over how many citizens from "visa waiver" countries have fought in Syria and, because of their citizenship, hold passports that enable them to travel relatively freely across Europe and potentially to the United States.
Many have joined an affiliate of al-Qaeda or rival group Islamic State that has seized territory and executed American and British hostages as well as hundreds in Syria and Iraq.