FILE PHOTO: An Air France Airbus A319 aircraft takes off at Paris Charles de Gaulle airport, following the coronavirus disease (COVID-19) outbreak, in Roissy-en-France, France March 16, 2020. REUTERS/Benoit Tessier

MONTREAL (Reuters) - International air passenger traffic could drop by as many as 1.2 billion travelers, or two-thirds, by September 2020, as the coronavirus pandemic weighs on demand, the United Nations aviation agency said on Wednesday in a statement, citing projections.

The International Civil Aviation Organization (ICAO) estimates that international capacity could drop by as much as two-thirds from previous forecasts for the first three quarters of 2020.

Coronavirus has led to widespread flight cancellations and grounding of aircraft.