RIO DE JANEIRO, June 6 (Reuters) - The head of the International Air Transport Association said on Saturday that rising jet fuel prices, driven by the ongoing war in the Middle East, are likely to push more airlines into bankruptcy and lead to further mergers in the sector during the current and next two years.

Global airlines are facing rising fuel costs due to the US-Israeli war on Iran, which has disrupted jet fuel supplies and key air routes, forcing them to take expensive alternative routes.

Low-cost airlines were among the hardest hit, as they lack higher-margin revenue streams such as luxury cabins, high-income travelers, and credit card loyalty programs.

Willie Walsh, the association's director general, said the effects of these pressures are already beginning to show, as the US budget airline Spirit Airlines collapsed last month, and it won't be the last.

"Unfortunately, I think some airlines will find it very difficult to cope with higher fuel prices," Walsh told Reuters at the IATA annual summit in Rio de Janeiro, adding that he expects some airlines to go bankrupt and larger airlines to acquire smaller ones.

However, Walsh said that these pressures do not mean the end of the low-cost carrier model, which continues to thrive outside the United States, as the three major airlines, United Airlines, Delta Air Lines and American Airlines, work to push low-cost competitors out of the market.

"I don't see the low-cost aviation model as having collapsed, quite the opposite," he continued, pointing to the strong performance of Ryanair in Europe as an example.

Iran’s war has disrupted traffic through Middle Eastern hubs such as Dubai, Doha and Abu Dhabi, causing significant challenges for Gulf airlines, including Emirates, Qatar Airways and Etihad Airways.

Walsh said he did not believe the conflict would cause lasting damage to the Gulf as an aviation hub, given its strategic geographic importance and the value of the renowned Gulf airlines, which represent 14 percent of global capacity.