In a statement issued Thursday, the AIIB said that "in the best interests of the bank, management has decided that all activities relating to Russia and Belarus are on hold and under review".

The bank added that it was "actively monitoring the situation" in Ukraine and that management would do the "utmost to safeguard the financial integrity of AIIB".

The multilateral financial institution, a brainchild of Chinese President Xi Jinping, was launched in 2016 to counter the West's dominance of the World Bank and International Monetary Fund.

Russia is among the AIIB's founding members and holds around a six percent vote in its operations. It also has a seat on the bank's board of directors.

It is the third-biggest stakeholder behind China -- which holds almost 27 percent of voting power -- and India.

Disclosures on the AIIB website show it has so far approved two Russia projects with financing of $800 million.

Only a small portion of its loan portfolio is in Russia.

Two projects for Belarus have also been proposed, in the fields of public health and transport.

"AIIB stands ready to extend financing flexibly and quickly and support members who have been adversely impacted by the war," the bank said, without giving further details.

While Russia and Belarus are members of the bank, Ukraine is not.

While majority of governments have reacted to Russia's invasion with sanctions, Beijing, which has close ties with the Kremlin, has taken a cautious line over the invasion -- neither condemning it nor voicing outright support.

Financial institutions and businesses around the world are scrambling to distance themselves from Russia and Belarus over the conflict.

The Shanghai-based New Development Bank, established around the same time and for similar reasons as AIIB, also said it has "put new transactions in Russia on hold".