New security screening for air passengers travelling from Canada to the United States went into effect on Wednesday.

Both Air Canada and WestJet are advising passengers to arrive at the airport at least two hours in advance because of the expected delays in getting through security checkpoints.

The new rules from the U.S. Dept. of Homeland Security require security agents to inspect all personal electronic devices such as phones, tablets, and laptops. That means travellers should make sure these items are easily accessible and have all cases and covers removed before going through the checkpoint.

There will also be more canine screening of baggage and use of advanced technology.

“We cannot play international whack-a-mole with each new threat. Instead we must put new measures in place across the board to keep travellers safe and make it harder for terrorists to succeed,” said John Kelly, the U.S. Department of Homeland Security Secretary.

Despite the warnings, on the first day the enhanced checks went into effect, the Canadian Air Transport Security Authority reported no delays.

“We've looked at the screening operations closely in Toronto and other airports. We haven't seen an increase in wait times,” said CATSA spokesperson Mathieu Larocque.

Kelly said measures both seen and unseen will be implemented over time.

The new regulation affects 325,000 daily passengers on flights from 280 airports in 105 countries.

Earlier this year the U.S. banned travellers from carrying laptops as carry-on items from ten airports in the Middle East and North Africa.