"These developments together make Asia the unrivalled centre of global oil trade as the region draws in rising shares of available crude oil," she told a news briefing in Tokyo, part of a roadshow to promote the agency's annual report.
She also said it was "too early to tell" what will be the impact of Iran's interim deal with major powers on its nuclear programme, which could eventually allow the huge oil producer to sell on the international market again.
The Paris-based IEA is an arm of the Organisation for Economic Co-operation and Development, an inter-governmental economic think tank among elite economies.
Van der Hoeven said that a move to non-traditional energy sources, including US shale gas, was opening the door to shrinking Asia's energy bill.
"Exports of liquefied natural gas from North America can act as a catalyst for those changes" and "accelerate a shift in the way gas is priced", she said.
Her comments come amid rising resentment over the so-called "Asian premium".
Japan, the world's biggest liquefied natural gas (LNG) importer, and some of its Asian neighbours have long paid more for LNG than nations in Europe and in North America.
That is because the region's contracts are often long-term and linked to oil prices, despite increasing global production of LNG, Japanese officials have said. Hefty prices for LNG have hit Japanese firms and utilities, which are now nearly entirely without working nuclear reactors because of a public backlash in the aftermath of the Fukushima atomic disaster.