The head of the Asian Development Bank says a continued engagement by the United States with Asia under President-elect Donald Trump would be good for both the region and America.

Takehiko Nakao, who began his second five-year term as president of the Manila-based development bank on Thursday, also said there is a strong case for regional agreements to liberalize trade and investment despite Trump's threat to withdraw from the 12-nation Trans-Pacific Partnership.

Nakao made the comments in response to questions about what would happen if Trump ends the current U.S. administration's emphasis on the region and pulls out of the TPP, which Trump called a "disaster" for American jobs.

Nakao said America's involvement in Asia has boosted the region's economy and stability.