OTTAWA—Canadian Prime Minister Justin Trudeau’s open-arms policy on refugees is facing pushback at home.

A poll published Friday by Vancouver-based Angus Reid Institute indicates Canadian anxiety over asylum seekers entering the country by foot from the U.S. has intensified from a year ago, when such border crossings hit a peak. Their concern “shows no sign of abating,” said Shachi Kurl, executive director of the polling organization.

According...