TOKYO — Asian Development Bank President Takehiko Nakao on Thursday called for more participation by the private sector in infrastructure development in Asia where such demand is expected to grow in the coming years.”

The private sector has been a very important player in public infrastructure investment for centuries,” Nakao said at a conference hosted by the ADB’s think tank in Tokyo, adding that public-private sector partnerships are important to meet infrastructure demand that is estimated to average around $1.7 trillion a year between 2016 and 2030.

Noting most of Japan’s railways were first built by private players before being nationalized for security and other reasons, the ADB chief said, “We need more resources.”

At the conference on managing private and local government debt, however, Nakao also acknowledged the difficulty of finding “good bankable projects” despite a lot of discussions about PPPs that use private-sector financing and expertise.

Building infrastructure is one of the key issues for Asia, particularly power, water, transport, and telecommunications facilities. According to ADB projections, growth in developing Asia is estimated to be 5.9 percent in 2017 and projected at 5.8 percent in 2018.

Since the launch of the Chinese-backed Asian Infrastructure Investment Bank, there have been fears that the presence of the ADB has been declining, even though Nakao expressed his view that his Manila-based lender can cooperate with the AIIB.