The United States says it will join Canada, Australia and Britain in sharing fingerprints and other data to help authorities discern people's true identities in cracking down on asylum shopping and unlawful immigration.

The program would allow governments to ferret out fraudulent refugee claimants by using fingerprinting and other methods to get details about identity, nationality, travel and immigration history.

Canada and the U.S. conducted a trial run two years ago in which authorities exchanged fingerprints on 343 refugee claimants.

One-third had applied to live in both countries and five per cent had a criminal history in the United States. U.S. Secretary of Homeland Security Janet Napolitano said such data sharing is effective.

"Biometrics continues to be a powerful tool to prevent terrorists and criminals from crossing our shared border and preventing identity theft and asylum fraud."

While David Fraser, a privacy lawyer in Halifax, has no problems with how international authorities intend to use the biometric information, he said they must ensure they stick to using the information properly.

"Once information goes into a large database it's very attractive to use it for other purposes and so it takes a lot of discipline, policy and procedure to make sure its use is confined to the only identified purpose."

Prints will be destroyed

Authorities in Canada say further personal information such as a passport number will be shared only when there is a fingerprint match and all fingerprints will be destroyed once people become successful refugee claimants or Canadian citizens.

Public Safety Minister Peter Van Loan said Canadians have no reason to fear their personal information will be shared with U.S. officials, because the program is aimed primarily at refugee claimants.

"The biometric information sharing is relating to refugee claimants and the refugee situation and some removals — it's more immigration-related," said Van Loan, flanked by Napolitano after a top-level meeting about border security attended by both the U.S. and Canadian ambassadors in Washington.

The biometrics announcement was one of a series of moves both countries are making to tackle common threats, Napolitano and Van Loan said.

Key measures include enhanced information sharing between the U.S. and Canada, the expansion of joint law enforcement operations and improved co-ordination during emergencies.

Napolitano skirted the question when asked if U.S. concerns about the Canadian border were escalating after two recent high-profile terrorism arrests in the United States with Canadian connections.

Tahawwur Rana, a Pakistani-Canadian who lives in the U.S., was arrested last month along with another Chicago resident, David Coleman Headley, on accusations of plotting to attack on a Danish newspaper for publishing cartoons in 2005 depicting the Prophet Muhammad.

The FBI has since alleged that Rana, 48, and Headley, 49, were in contact with the Pakistani group Lashkar-e-Taiba, which the Indian government blames for last November's terrorist attacks in Mumbai that left 166 dead and 308 wounded.

In September, Najibullah Zazi, 24, was arrested in Denver and accused of plotting to blow up targets in New York in what has been billed as biggest U.S. terrorist attack since 9-11. Zazi, who has family living near Toronto, travelled twice to Canada in the months before his arrest.

With files from The Canadian Press