Toronto schools have stopped planning field trips to the United States, citing concerns that some students may be turned away at the border in the wake of President Trump’s latest travel ban and the American immigration authorities’ newly implemented “extreme vetting” procedures.

At the same time, many Canadian universities are seeing a sharp increase in international student applications while foreign applications to many colleges in the United States have declined.

The field trip decision by the Toronto District School Board, the largest board in the country, was the latest disruption in travel from Canada to the United States as the Trump administration tightens the borders. Canada’s Girl Guides and the Greater Essex County District School Board in Windsor, Ontario, earlier suspended trips across the border given the uncertainties surrounding the ban.

“We don’t want to put our students in the position of traveling down to the border with their friends and classmates on a trip and then being told they cannot enter the U.S. for no legitimate reason,” said Ryan Bird, a spokesman for the Toronto board.