The US government said this week it will go ahead with plans to require travellers from Canada, Mexico and other allied nations to show a passport or other secure document to enter the country.

The departments of State and Homeland Security said they expect to officially adopt the new policy ? which drew complaints from travellers, the affected nations and even President George W. Bush ? by the end of the year. But they pushed back by a year the date when the requirements would begin to affect travellers.

Under the new timeline, all who travel by air or sea from Canada, Mexico, the Caribbean, Bermuda and South and Central America will have to show a passport or one of four other secure documents by December 31, 2006.

Travellers crossing land borders, namely from Mexico and Canada, will have to comply with the rules by December 31, 2007.

Department officials also said they will keep working to come up with a cheaper, more widely used alternative document to allow US citizens and other travellers to cross into the country over land borders.

After the rules were announced in April, Mr. Bush said he was surprised by the passport requirement, which drew sharp criticism from the Canadian government, and said he had ordered a review of the plans. Last December, Mr. Bush signed into law an intelligence overhaul that requires tighter border security and was the basis for the passport proposal.

Homeland Security spokesman Jarrod Agen said the administration is looking to use biometric technology in creating an alternative identification card before the 2007 deadline. Despite moving forward with the plans, ?this gives us time to develop the most sensible and secure document which won?t stop the flow of traffic at the border,? he said.