A Qantas Boeing 737-800 takes off from Sydney's Kingsford Smith airport on November 1, 2019. Photo: AFP / Peter Parks

Australian airline Qantas on Thursday posted more than US$1 billion in annual losses, after what it described as a “diabolical” year caused by pandemic travel restrictions.

The national flag carrier reported A$1.83 billion (US$1.33 billion) in underlying pre-tax losses for the 12 months to June 30, rising to A$2.35 billion (US$1.7 billion) when including one-off costs such as redundancy payouts and mothballing aircraft.

It comes on top of almost US$2 billion in statutory pre-tax losses reported in the previous financial year, when airlines globally were hit with the initial impacts of the coronavirus pandemic.

Qantas CEO Alan Joyce predicted the airline’s revenues will have plunged more than A$20 billion (US$14.5 billion) by the end of 2021 as a result of Covid-19.

“This loss shows the impact that a full year of closed international borders and more than 330 days of domestic travel restrictions had on the national carrier,” he said in a statement.

“The trading conditions have frankly been diabolical.”

The airline said periods of open borders within Australia in early 2021 had briefly boosted revenue, but a return to internal restrictions after a prolonged Delta variant outbreak in Sydney has forced the widespread cancellation of flights.

Australia, which has recorded almost 47,000 infections and 986 deaths to date, is battling a resurgence of coronavirus that has left more than half the country’s population under lockdown.

In addition to thousands of pilots and cabin crew being stood down or made redundant in 2020, Qantas recently announced 2,500 more would be stood down in response to the latest outbreak.

Qantas now hopes to return to international flights by the end of 2021, naming countries with high vaccination rates such as the United States, Britain and Singapore as potential early destinations.

However, none of the airline’s previous optimistic predictions on the revival of overseas travel has been met and the government is yet to announce when Australia’s strict border controls will be eased.