https://www.voanews.com/a/canadian-officials-in-nigeria-work-with-us-to-stem-asylum-seekers/4376636.html
The Canadian government is trying to stem the flow of asylum seekers illegally walking across the U.S. border even as their ranks grow: About 2,500 asylum seekers crossed into Canada to file refugee claims in April, according to estimates from the federal immigration and refugee department — the highest level since August and almost triple last April's figure.
More than 26,000 people illegally crossed the Canada-U.S. border in the past 15 months to file refugee claims.
The Canadian government says many of the more recent arrivals are Nigerians who arrived bearing valid U.S. visas after having spent very little time in the United States.
“It is apparent that they obtained those visas with the express intent to actually go to Canada. ... We’ve been sharing that information with the United States with the view of preventing the abuse of U.S. visas,” a Canadian immigration department spokeswoman told Reuters in an email.