Canada's largest school board says it will stop booking trips to the United States indefinitely in light of the uncertainty surrounding restrictions at the border.

The Toronto District School Board, which serves about 245,000 public school students, says it made the "difficult decision" because it believes students "should not be placed into these situations of potentially being turned away at the border."

The board says that for now, it will move forward with the 24 U.S. trips that have already been approved, but says the entire group will turn back if any students with appropriate documentation are turned away.

"We're committed as a school board to equity, inclusiveness and fairness, and it's not appropriate that some students would not be able to attend based on their country of birth," said TDSB chair Robin Pilkey.

Existing trips will be cancelled and refunded if the U.S. enacts any rules that would bar certain students from crossing the border, according to the board.

Pilkey said about 800 students from 24 schools are affected at this point.

She said that the decision has brought forward questions from parents, students and staff, but overall there has been a positive reaction, especially from students.

U.S. President Donald Trump announced new travel restrictions earlier this month that would affect who can enter the country, but those changes have been on hold as they face several court challenges.

The school board said it will continue to monitor the situation and may revisit its decision if it receives new information.

As for whether the current decision will make students miss out on the opportunity to travel and compete in international competitions, Pilkey thinks it could be the impetus needed to bring similar events here.

"We would have to consider whether this is something we should be trying to run in Canada," she said.

"There should be an ability for us to do this here if we'd like to."