The emerging omicron variant of the coronavirus, named a cause for concern by the World Health Organization on Friday, is starting to have an impact on business travel and thus hopes for a fuller recovery for the hotel industry.

“There’s a period of uncertainty right now," easyJet CEO Johan Lundgren said on Tuesday during the company's most recent earnings call, adding that the airline, which is one of Europe's largest, is seeing bookings drop somewhat as travelers delay flights.

A number of countries, including the United States, have restricted flights from southern Africa, while other countries, such as Japan and Israel, have barred entry to noncitizens completely or tightened rules for entry.

Unease about new travel restrictions has discouraged some business travel, The Wall Street Journal reports, citing a postponed trip by Nestlé SA executives to London after the UK tightened its entry rules.

"I think the year-end holiday travel is booked and will go forward," Philip Baggaley, chief credit analyst for airlines at Standard & Poor's, told CNN. "But the plans for international travel and business travel, I would imagine there will be a wait-and-see attitude."

Even before the omicron variant, business travel, which is a mainstay of the hospitality industry, hadn't come close to recovering to pre-pandemic levels.

"As kids headed back to school, individual business travel and group demand that historically replaces summer leisure business post Labor Day has yet to surface, with office re-openings pushed later into 2021 or early 2022 as a result of the delta variant of the virus," PwC noted in a report on U.S. hospitality in November.

In mid-November, the Global Business Travel Association reported that North America led the recovery in spending on business travel thus far in 2021, seeing a rebound of 27% in 2021 compared with the year before.

Even so, the organization warned of a rocky road ahead.

"The business travel industry recognizes there are factors, related to Covid-19 and beyond, that could impact the road ahead over the coming years," GBTA CEO Suzanne Neufang said in a statement.