ALBANY, N.Y. – New York, New Hampshire, Vermont, Maine and Quebec will join a U.S.-Canada initiative aimed at intercepting containerized freight shipments loaded by terrorists with dangerous materials, New York Gov. George Pataki announced Thursday at a homeland security conference.

At the same conference, federal officials announced that the 50 busiest U.S. border crossings, including Calais Ferry Point in Maine, were implementing a new computerized screening system to identify foreigners wanted for immigration or criminal violations.

As part of the freight initiative, the states and Canadian province will test strategies for sharing information among federal, state and local law enforcement officials if a suspicious shipment is detected. They will also develop radiation detection capabilities for freight passing across their borders, Pataki’s office said.

“A significant goal of this phase of the project will be to assess the extent that law enforcement and private security professionals can share real-time information,” said James McMahon, New York’s homeland security director.

Pataki outlined the new agreement at a regional conference Thursday of homeland security and law enforcement officials from New York, Maine, New Hampshire, Ohio, Pennsylvania, Vermont and Canada.

U.S. Attorney Glenn Suddaby said a computerized system for tracking and protecting freight containers against tampering could be in use within a couple of years. Remaining issues include business involvement and the pass-through to consumers of costs, she said.

Asa Hutchinson, the federal Department of Homeland Security’s undersecretary, said his agency has tripled the number of agents patrolling the northern border since the Sept. 11, 2001, terrorist attacks. An aide said there are now 1,042.

In 2003, customs and border patrol agents stopped 103 aliens along the northern border “for concerns involving terrorism or national security violations,” with another 90 “intercepts” in 2004, Hutchinson said. Most were “turnaways,” denied entry to the United States, and none was directly charged with terrorism or supporting terrorism, he said.

The first phase of the initiative to monitor the safety of commercial traffic between Canada and the northeastern United States included an inventory of tracking and security technologies for shipping containers and the test-tracking of a shipment that originated in Slovakia.

Pataki’s office said that as commercial supply routes between Canadian ports and commercial businesses in Canada and the United States are better studied, security measures can be enhanced.

Most of the world’s commerce spends time in transit in the shipment containers, which can be carried on ships, trains and tractor-trailers.

Pataki said one aim of the multistate and province initiative is to make sure that the flow of commercial traffic is not being unduly hampered by the security screening process.

At the same conference, federal officials discussed the new computerized screening system that will be used at the busiest U.S. border crossings, including one in Calais, Maine.

At airports, the U.S. VISIT system has resulted in 1,600 watch list “hits” among 13.5 million travelers since January, Hutchinson said. That included a Nigerian woman who committed a 1996 crime in North Carolina and was caught with a finger scan when she tried to re-enter the United States with a false passport in Atlanta.

The 50 busiest land crossings, 17 along the northern border, will have the system by the end of this year as scheduled, Hutchinson said. Already at U.S. seaports, its use will expand again next year and is scheduled to reach all entry points in 2006.

“Our carefree approach to the northern border has been destroyed. It is no longer applicable,” Hutchinson said.