Israel has become the newest non-regional member of the Asian Development Bank, the Philippines-based lender announced Friday, with an analyst cautioning that the move might cause "polarisation" in the institution.

The bank's board of governors had approved Israel's entry in April 2022 pending its completion of the membership requirements, the ADB said in a statement.

Israeli Finance Minister Bezalel Smotrich will be the country's representative, a source from ADB told AFP.

The bank now has 69 members, with Japan and the United States the major contributors to its capital, at more than $22.23 billion apiece.

"They (Israel) are allied with US, and basically Europe right, but they would want to also... have more friends across the globe, not only those that have been traditionally allied with them," said economist Victor Abola, of the Manila-based University of Asia and the Pacific.

"The greater involvement here means closer strategic ties and trade," Abola told AFP.

Security analyst Chester Cabalza, however, said Israel joining the ADB in the midst of its war in the Gaza Strip could lead to "other members fleeing the organisation" in favour of the China-led Asian Infrastructure Investment Bank (AIIB).

"Or we (may) see polarisation in the ADB as long as Israel will not resolve its security issues in Gaza," Cabalza told AFP.

The ADB includes several Muslim-majority Asian member nations that have been critical of Israel's handling of the war.

Established in 1966, the ADB is owned by its 69 members, 49 of which are in Asia.

Israel, which first applied for membership in January 2022, is the 20th non-regional member.