The cards will cost $45, compared to $100 for traditional passports and U.S. officials are encouraging applicants to apply now to receive the first of the new cards in four weeks, The Arizona Republic reported Monday.

New rules instituted to help prevent terrorism mandate that U.S. citizens who cross land borders into Mexico or Canada will need to show a passport to re-enter the country after June 1, 2009. The wallet-sized passport, embedded with a radio frequency chip is meant make frequent crossings easier, the newspaper said.

Officials said they expect many millions of the passport cards to be in circulation after a few years.