Refugee support groups on both sides of the Canadian-U.S. border are criticizing a new agreement dealing with refugees.

The Safe Third Country Agreement, formally signed in Washington this week, stipulates that refugees must seek asylum in whichever of the two countries they reach first.

When it was introduced, Deputy Prime Minister John Manley said it would eliminate "the practice of asylum shopping by refugee applicants by allowing their return to the last safe country from which they came."

The agreement makes exceptions for people who have relatives in Canada, people who make a claim at an airport or inland office, and for children.

Preventing individuals who first set foot in the U.S. from making a claim in Canada will increase cases of human smuggling, critics say. Other refugees will be forced to live without any kind of legal status in the U.S., they say.

At Vive La Casa, a refugee shelter in Buffalo, N.Y., the flow of refugees is mostly one-way to Canada.

Many at the shelter say they feel the Canadian refugee system is more compassionate, and the Canadian social system more accommodating.

Vive La Casa director Chris Owens says about half of the 6,000 people, who pass through the shelter here each year will soon be turned back at the Canadian border.

The new agreement won't go into effect until early next year. But Owens is already worried about the risks some people will take crossing the Niagara River to enter Canada illegally.

"I think we're going to see on the U.S.-Canadian border a situation which we have seen for many years on the U.S.-Mexico border and that is hundreds of thousands of people crossing illegally, many of them in terrible danger as they cross," he says.

It's not just refugee groups that say the Safe Third Country agreement will lead to dangerous trips across the Niagara River and lead to more organized human smuggling.

Ed Duda, deputy chief of the U.S. Border Patrol stationed in Buffalo, says he is anticipating more people will attempt an illegal entry into Canada.