IAG reported a 25% rise in pre-tax profits to â‚¬449m (Â£315m) for the three months to 30 June.
Chief executive Willie Walsh told the BBC's Today programme the results "reflect the underlying strength of the airlines".
IAG is in the process of buying Irish carrier Aer Lingus.
The group is still waiting for approval from stakeholder Ryanair, which Mr Walsh is confident they will receive.
"What Ryanair has said is that they do intend to sell us their stake," he said.
Mr Walsh also said the weakening euro had an impact on the company's results in the first half of the year: "We continue to take cost out of the business, with both employee and supplier unit costs down at constant currency, and improvements in productivity levels," said Mr Walsh.
The company said that at current fuel prices and exchange rates, IAG's outlook remains unchanged.
Since the formation of IAG through the merger of BA and Iberia in 2011, Iberia has been undergoing a massive restructuring programme, with jobs and salaries being cut.
British Airways (BA) owner International Airlines Group (IAG) has reported a big jump in quarterly profits.