WASHINGTON, United States (Reuters):

The U.S. State Department on Tuesday proposed developing a wallet-sized 'passport card' that would allow American citizens to travel to Canada, Mexico, Bermuda and parts of the Caribbean.

The card is designed to speed the travel of the millions of Americans who go to Canada and Mexico by land as well as those who visit some Caribbean nations on cruises.

At present, such travelers typically do not need passports and the card - if developed - would create a new travel document that would be more secure and uniform than a U.S. drivers' license or birth certificate, a U.S. official said.

The State Department said the card itself would not contain personal information but - using radio technology - would link to a government database that would contain a photograph and biographical data.

The proposal, which is being submitted for public comment before it can be carried out, was criticised by Senator Patrick Leahy, a Vermont Democrat, who said in a statement it would "risk the personal information of millions of Americans."

The State Department said obtaining the proposed card would cost adults US$45 and children US$35. In contrast, applying for a passport costs US$97 for adults and US$82 for children under 16.