Airlines may be reluctant to take delivery of aircraft due to the ongoing uncertainty around U.S. tariffs and their impact on the cost of the planes, International Air Transport Association Director-General Willie Walsh said on Wednesday.

"It's not just going to be a major Boeing and Airbus issue. It'll impact all aspects of the aerospace industry and have an impact on most, if not all, airlines as well," he said.

Walsh was speaking at a media roundtable in Singapore.

The 50% tariff that President Donald Trump plans to impose on Brazilian exports starting in August could hammer the revenue of planemaker Embraer like the COVID-19 pandemic did, its CEO warned on Tuesday, flagging risks to U.S. partners.

Francisco Gomes Neto told reporters the tariffs would amount to a trade embargo on the regional jets it supplies to U.S. airlines and could trigger order cancellations, deferred deliveries and tough consequences for Embraer's U.S. suppliers.