"Infrastructure needs are huge and it's simply not possible for the Asian Development Bank and the World Bank to fill the -gap completely," Kuroda, who was formerly head of the ADB, told a seminar hosted by an ADB-affiliated think tank on Tuesday.

He said healthy competition from Chinese, Indian and Japanese initiatives could be positive for improving infrastructure and boosting economic growth and social inclusiveness.

Kuroda's remarks are the strongest endorsement to date by a Japanese policymaker over the growing presence of AIIB, which some in Tokyo see as a vehicle to boost China's regional clout.

The AIIB has been viewed as a rival to the Western-dominated World Bank and the ADB, which is jointly led by the United States and Japan. The United States initially opposed the AIIB's creation and is not a member, but many U.S. allies, including Canada, Britain, Germany, Australia and South Korea have joined.

Japan, following Washington's lead under then-U.S. President Barack Obama, did not join the AIIB as well, partly from concern it would conflict with the ADB, the Manila-based institution dominated by Japan and the United States.

But Kuroda said the establishment of AIIB and the fact it attracted many members were a "good" thing as they help meet rapidly increasing infrastructure-funding needs in the region.

"The ADB has promoted regional cooperation in Asia. It also tried to link regional initiatives with each other. That is the way we should go forward, rather than making a single Asia program or an Asia initiative," he said.

Kuroda also urged politicians to contain geopolitical conflicts which is "not good for anyone."

(Reporting by Leika Kihara; Editing by Chris Gallagher and Sam Holmes)