The Manila-based bank said the loan, as additional financing to the ongoing Infrastructure Preparation and Innovation Facility (IPIF), will support the preparation of several transformative projects, including the detailed engineering design of an interlink bridge that connects the provinces of Bataan and Cavite and the Metro Rail Transit Line 4.

It will also provide project implementation and preparation support for staff at the country's Department of Transportation and the Department of Public Works and Highways, so they can effectively and efficiently manage complex infrastructure projects, the bank added.

"Usually, major infrastructure projects take at least five years to prepare. But the government's 'Build, Build, Build' program has significantly shortened this preparation period, and the IPIF support is helping with this," said ADB Country Director for the Philippines Kelly Bird.

"From a historical perspective, the government's rollout of its 'Build, Build, Build' program has been incredibly successful, with public spending on infrastructure at an all-time high," Bird added.

The program, a main focus of the Duterte administration, aims to boost long-term economic growth by increasing public infrastructure investments to 7.0 percent of gross domestic product by 2022.

According to ADB, public spending on infrastructure has been on an uptrend in the Philippines, reaching over 5.0 percent in 2018, up from around 3.0 percent in 2015 before President Rodrigo Duterte assumed office in June 2016.

IPIF was initially set up with a 100 million U.S. dollars loan approved by ADB in 2017 to help the government tap into international best practices in preparing flagship infrastructure projects, including railways, roads, bridges, and flood protection facilities.

It also provided government officials access to innovative technologies in preparing technically complex projects, such as long-span bridges, the bank said.