PARIS/LONDON (REUTERS) - The head of global airline industry body Iata blames overly risk-averse governments for prolonging the Covid-19 crisis for the travel sector, but expects the outlook to brighten in the second half of the year.

Iata director-general Willie Walsh, the former boss of British Airways owner IAG, expects positive data on vaccine effectiveness to convince governments to start rolling back restrictions.

"There is some good evidence there to be optimistic that, going into the second half of this year, we will see a better environment that will allow more people to travel," he told Reuters on Friday (May 28).

Most international air travel remains depressed almost 18 months into the pandemic because of continuing restrictions.

Mr Walsh, who took the top job at Iata in April, said that governments are being too risk-averse and need to change rules to reflect data showing that vaccinated travel or travel with testing poses little risk to a country's infection rate.

"The crisis in the airline industry, which was initially caused by a health pandemic, is now really a crisis caused by restrictions being imposed by government," he said.

He singled out Britain in particular, citing rules that require people entering the UK from nearly all countries to take at least two coronavirus tests and enter quarantine. Mr Walsh also hit out at what he said was "incredible farcical confusion" created by mixed political messages on travel.

Many countries on Britain's "amber list" for medium-risk travel have very, very low transmission rates, said Mr Walsh.

"If I was vaccinated, I wouldn't hesitate to fly to these countries," he said of places such as the United States, Spain, France and Italy, which were top destinations for Britons before the pandemic.

Britain said its cautious approach to the return of international travel was designed to prioritise public health.

"Country classification... is guided by the evidence and analysis of a range of key factors, including rates of infection, the prevalence of variants of concern, and the country's access to reliable scientific data and genomic sequencing," a Department for Transport spokesman said.

Britain and the US both have high vaccination levels, which Mr Walsh said gives him confidence that a travel corridor could be opened between the countries in June.

"I think there's a good reason to be optimistic that we should be able to see the UK and US open transatlantic flying again," he said.