The Bush administration on Friday temporarily waived some of its new, post-Sept. 11 requirements for flying abroad, hoping to help irate summer travelers whose trips have been jeopardized by delays in processing their passports.

The change would aid those fliers awaiting a U.S. passport to meet the new rule requiring one for travel to Canada, Mexico, the Caribbean and Bermuda. But it won't clear the way for travelers who haven't already applied for a passport.

There is still no passport required for Americans driving across the Canadian or Mexican borders or taking sea cruises, although those travelers are expected to need passports under new rules beginning next year.

Easing the rules should allow the State Department to catch up with a massive surge in applications that has overwhelmed passport processing centers since the rule took effect this year, officials said. The resulting backlog has caused up to three-month delays for passports and ruined or delayed the travel plans of thousands of travelers.

Until the end of September, travelers will be allowed to fly without a passport if they present a State Department receipt, showing they had applied for a passport, and government-issued identification, such as a driver's license.

Travelers showing only receipts would receive additional security scrutiny, which could include extra questioning or bag checks.

The passport rule would only affect those who have already applied for passports — not those who apply in coming days for travel later this summer.  Individuals who have not yet applied for a passport should not expect to be accommodated.

The application surge is the result of the Western Hemisphere Travel Initiative that since January has required U.S. citizens to use passports when entering the United States from Canada, Mexico and the Caribbean by air. It is part of a broader package of immigration rules enacted after the Sept. 11, 2001, terrorist attacks.

The department received 1 million applications in December, 1.8 million January and 1.7 million in February. Turnaround times for passports were bumped up from six to 10-12 weeks after the surge, but 500,000 applications have already taken longer, she said.  However, the agency expects to eliminate the backlog and meet the new standard of 10-12 weeks before the end of September, she said.

Homeland Security has insisted it plans to go ahead with a January 2008 start for requiring passports at all land border crossing in the United States — a security measure that could trigger a new frenzy of applications.

The State Department is still working on creating a cheaper, passcard alternative for such land crossings.