MANILA, March 11 (Xinhua) -- The board of governors of the Asian Development Bank (ADB) has approved the membership of Niue as the bank's 68th member and 49th in the Asia Pacific region, the Manila-based bank said on Monday.

"We welcome Niue as ADB's newest member. This new relationship will bring Niue into the development community and help ADB to work closely on building and strengthening economic growth that benefits all Niueans," ADB President Takehiko Nakao said in a statement.

Located on the east of Tonga and on the south of Samoa, Niue is an island country in the South Pacific Ocean. It is one of the smallest countries in the world with an estimated population of 1,624 in 2016.

The country faces serious challenges in achieving sustained social and economic development, according to the ADB.

The bank said Niue's development has benefited from its close relationship with New Zealand and support from other bilateral development partners and regional organizations.

Niue's economy grew by an average of 3.6 percent per annum during 2012 to 2016. The development of tourism has been the main driver of its growth.