Leveraging private capital and technical expertise through public-private partnerships (PPPs) can help countries in Asia and the Pacific meet their infrastructure needs, which currently stand at about 1.7 trillion U.S. dollars per year, a new Asian Development Bank (ADB) report said on Tuesday.

The report said that Asia's infrastructure needs dwarf traditional sources of finance needed to address the region's huge infrastructure needs.

Over 400 million Asians live without electricity, 300 million without safe drinking water, and a staggering 1.5 billion without basic sanitation, said the special theme chapter in the updated Asian Development Outlook (ADO) 2017, ADB's flagship economic publication.

"The region will need to invest an estimated 1.7 trillion U.S. dollars annually through 2030 to maintain its growth momentum, reduce poverty, and respond to climate change," the report said.

Further, it said the financing gap to meet these investment needs currently approaches 500 billion U.S. dollar per year.

"While state funds currently finance 92 percent of the region's infrastructure investment, some economies struggle to meet these needs, constrained by high fiscal deficits and deepening public debt," the report said.

"PPPs, if done right, have the potential to fill the region's huge infrastructure needs, leveraging the capabilities and resources of the private sector towards the common goal of sustainable development for all," said ADB chief economist Yasuyuki Sawada.

"Resources of governments and international financial institutions like ADB are not enough to meet these needs -- something the private sector through PPPs can help address," the report said.

The PPP model has been gaining ground in Asia, with project delivery through the scheme in the region growing fourfold in the last 25 years, according to the report.

Analysis of private participation in infrastructure database shows that the number of PPP projects in developing Asia grew by 11 percent annually from 1991 to 2015.

"The region accounts for half of all projects in 139 developing economies worldwide, followed by Latin America and the Caribbean with 30 percent. However, the distribution of PPPs is uneven across economies and sectors within the region," the report said.

Energy and transport have been the traditional focus for PPP projects, while health and education represent new frontiers in PPP delivery, the report further said.

To effectively implement PPP schemes in development projects in Asia and the Pacific, the report stressed the need to improve the governance, legislation, institutional structures, and PPP know-how.