Top executives of Emirates and Etihad, two of the Middle East's biggest airlines, have said passenger demand may not return to pre-coronavirus crisis levels until 2023.

About 85 percent of the world's airlines could face financial distress by the end of the year without government aid, Emirates President Tim Clark and Etihad CEO Tony Douglas told a video conference hosted by the US-UAE Business Council last week.

Clark and Douglas reiterated their beliefs that until an effective vaccine for the COVID-19 respiratory disease becomes widely available, how passengers fly will be different, a statement by the council said.

Lasting restrictions like 14-day quarantines, testing, and social distancing will impact demand and operations, they said. 

The airlines could not be reached for comment.

Emirates and Etihad, which operate fleets of over 370 aircraft, a majority of them wide-bodied, have grounded their operations in March and are serving limited outbound flights to take repatriate foreigners from the United Arab Emirates.

Dubai is expected to resume welcoming tourists by July, more than four months after halting the vital sector due to the coronavirus pandemic, an official said.

The return however will be gradual and could be delayed until September, Helal al-Marri, the director general of Dubai's Department of Tourism and Commerce Marketing, told Bloomberg TV last week.

A majority of global airlines have also stopped operations due to shutdowns imposed to counter the spread of the novel coronavirus.

The International Air Transport Association has repeatedly called on governments to provide generous aid to airlines.

IATA said on April 23 that air traffic in the Middle East and North Africa is set to plummet by more than half due to the virus crisis.

It also said that MENA airlines' revenues are forecast to slump by $24.5 billion this year compared to 2019.

The International Civil Aviation Organization, a UN agency, said last month that the pandemic could mean 1.2 billion fewer air passengers worldwide by September.

IATA has urged governments to offer airlines direct financial support, loans and tax relief.