SAN FRANCISCO, Sept 11: The US administration has decided to postpone the enforcement of new passport regulations that threatened to block millions of Western Europeans and citizens of other developed nations from travelling to the United States unless they obtained new, computer-coded passports, US officials said.

The new passport rules, which were supposed to take effect on Oct 1 and which were mandated by Congress as an anti-terrorism measure, will not be enforced until October 2004, the officials said.

US officials said that the State Department had decided to delay the rules by more than a year because of the chaos that could have resulted when travellers unaware of the new rules tried to enter the United States with older passports.