It is planning to operate around 45 per cent of passenger capacity between July and September compared with the same period in 2019.
That is up from 21.9 per cent during the previous three months.
Capacity for flights to the most popular leisure destinations this summer will exceed what was recorded in 2019, IAG chief executive Luis Gallego said.
He added that the firm is "ready to fly as much as 75 per cent of 2019 capacity" in the final three months of the year.
But the company warned that its plans "remain uncertain and subject to ongoing review".
It added that it "continues to be adversely affected by the Covid-19 pandemic together with government restrictions and quarantine requirements".
IAG posted an operating loss of £1.73bn for the half-year to June 30, representing a reduction from the £3.45bn loss it saw for the same period in 2020.
Mr Gallego said: "In the short term, our focus is on ensuring our operational readiness, so we have the flexibility to capitalise on an environment where there's evidence of widespread pent-up demand when travel restrictions are lifted.
"We know that recovery will be uneven, but we're ready to take advantage of a surge in air travel demand in line with increasing vaccination rates.
"We welcome the recent announcement that fully-vaccinated travellers from amber countries in the EU and the US will no longer have to quarantine upon arrival in the UK.
"We see this as an important first step in fully reopening the transatlantic travel corridor."
Mr Gallego said British Airways saw a 95 per cent increase in the number of bookings for flights from the US to the UK shortly after Wednesday's announcement on easing travel rules, compared with the same period last week.
Asked if the planned ending of the furlough in September could lead to more UK job losses, he replied: "What we would like is to have an extension of the furlough scheme until the end of the year."
He added: "Right now, we are not considering to reduce jobs more, but for sure we need to see the evolution of the situation.
"With the plans that we have right now, our plan is to fly, people want to fly, and for that we're going to need our people."
In April 2020 British Airways announced it would cut up to 12,000 jobs in response to the virus crisis.
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