The travel and hospitality sector was left reeling Wednesday after the federal government warned against non-essential trips abroad due to alarming numbers of COVID-19 cases.

WestJet CEO Harry Taylor railed against the advisory, predicting it will create “unnecessary disruption and chaos'' ahead of the holiday travel season.

“Fully vaccinated Canadians should not be singled out for choosing to take part in a safe activity,'' Taylor said in a release.

“Travel bans, restrictions and blanket advisories are devastating to the continued economic recovery of the country and place tens of thousands of recently recalled Canadian travel and tourism jobs at risk.''

He also claimed the government's warning is “not based on science and data,'' adding that Canada's travel measures are out of step with border policies in the European Union, United Kingdom and United States.

The statement came after a news conference in Ottawa in which Health Minister Jean-Yves Duclos said the Omicron variant is now spreading in Canadian communities and across the globe, prompting a new advisory less than two months after the old one was lifted.

Duclos said the situation became more complicated at a pace he “couldn't have imagined'' a few weeks ago.

“To those who were planning to travel I say very clearly, now is not the time to travel,'' he said.

“I know this is difficult for airlines, for travel agencies, for families, for people who haven't been able to see each other for a long time,'' Duclos added in French.

Airline customers have been cancelling bookings by the thousands, said Air Transport Association of Canada CEO John McKenna.

“They're cancelling because they don't know what to expect when they come back,''  McKenna said in an interview.

“I think they're more afraid of the bureaucracy than of Omicron.''

A decline in international trips will likely prompt a slowdown in regional ones, since the two feed into one another, and anxiety over the highly transmissible strain will further discourage domestic travel, he said.

The Association of Canadian Travel Agencies says the new advisory will have a “devastating impact'' on its 14,000 agents, who depend on holiday travel to bolster business.

The trade group is urging Ottawa to communicate advisories and border measures clearly and quickly on a single website and work more closely with industry.