Washington ? The Bush administration will delay for at least six months a rule that Americans present passports when crossing the U.S. border by land or sea, officials said Wednesday.

The announcement marks the second time in a month that officials have scaled back security plans in response to complaints.

Beginning in January, land and sea travelers returning from Canada, Mexico, the Caribbean, and Bermuda will be allowed to present a birth certificate and driver’s license in lieu of a passport.

The modification is expected to last at least until the summer of 2008, when officials hope to require passports or similar documentation at all land and sea crossings.

Homeland Security Secretary Michael Chertoff announced the proposed rules and new flexibility after a passport requirement for air travel to those countries produced monthslong delays in processing passport applications at the State Department.

Both houses of Congress have addressed the issue and called for suspension of the rules.