Officials with Toronto Pearson International Airport announced an updated screening process on Tuesday for passengers headed to the United States.

The revamped Security in Advance (SIA) protocol requires travellers to first pass through Canadian security, then U.S. customs. Previously, travellers visited U.S. customs first.

Officials gathered at Pearson International Airport Tuesday to celebrate the opening of a new security checkpoint for travellers going to the U.S. (CBC) "What we've done here is to put, if you like, the cart behind the horse, instead of in the reverse order," Canadian Minister of Transport Marc Garneau said after the announcement.

That adds more security for passengers and customs personnel, as baggage will be screened prior to entering the customs area, he said.

"This is something that our American neighbours felt strongly about. We agreed with it," he said. "It's the way it is in six of the eight airports where we do have pre-clearance and we've now corrected it here in Toronto."

The switch also opens up travel to American destinations where local airports don't have a customs set-up, he said.

The last phase of the switch was completed on May 17, when a new checkpoint and several pre-board screening lines opened in Terminal 1, but officials made the announcement Tuesday. The terminal 3 checkpoint has been functional since January.

The switch was completed after a two-year collaboration between U.S. Customs and Border Protection (CBP), Canadian Air Transport Security Authority (CATSA) and air carriers.

Pearson airport is the fourth largest air entry point into the U.S., with 5.6 million passengers flying from Toronto to the U.S. each year.