The airline said passenger numbers in the first three months of the year were just 19.6% of levels seen in 2019, as it recorded a pre-tax loss for the period of 1.22 billion euros (£1.1 billion).
IAG chief executive Luis Gallego said sales of seats in the three months between April and the end of June remain at 25% of levels in 2019 and governments must step up to provide support for reopening.
He said travel corridors without restrictions; affordable and simple testing; contactless border controls and digital vaccination and testing passports were required.
Mr Gallego added: “These measures will enable a safe re-opening of our skies. Travel underpins a global industry that supports 13 million jobs in Europe alone.
“There’s a high level of pent-up demand and aviation will play a critical role in reconnecting people and getting economies back up and running again.”