ATLANTA —Americans are putting an unusual strain on passport offices because of new US rules requiring them to carry the documents for air travel to Canada, the Caribbean and Latin America.

The average processing time has risen to 10 weeks from six because of the rules imposed on January 23 to comply with the Intelligence Reform and Terrorism Prevention Act of 2004, the State Department said on Friday.

Expedited passport services, which cost more and usually take 2 weeks, now take three to four weeks and sometimes longer and US customer-service centers are struggling to cope with the higher volume of calls and e-mails.

February to April is the peak period for passport applications as many Americans plan trips abroad for the Spring Break holiday and summer, the State Department said. It hired several hundred additional staff but there were still delays.

The new rules were a "total disaster," said Phillip Overton, owner of a Carlson Wagonlit Travel franchise in Dallas. Many travelers were unaware they needed passports until it was too late, he said.

"You have a lot of people buying online products and tickets and they don’t know that they have to have a passport ... so we are getting calls all the time from people who have not even booked with us who are panicking," Overton said.

"A lot of people don’t even understand what they (passports) are," he told Reuters.

The problem could become more severe next January when US citizens will need passports also for land and sea travel to the same areas, the only exceptions being US territories such as Puerto Rico and the US Virgin Islands.

Over 74 million US citizens have passports, according to government figures. Previously many Americans used other identity documents such as birth certificates for travel.

Under US rules Canadians traveling to the United States by air also are required to carry passports.

Canada’s passport authority said it had processed over 1 million applications since November and was receiving around 20,000 applications a day from people required to comply with the US regulations.

Applicants could expect to wait up to 45 business days for a new passport, according to the Passport Canada Web site.

Some travel agents said they had taken the changes in stride, in part by advising callers who booked travel to obtain passports in good time, though one noted that the extra expense was hurting some families with children. —Reuters