World Bank President Ajay Banga said Tuesday that proposed new contributions from rich countries under capital adequacy could boost the bank's lending capacity by about $100 billion to $125 billion over a decade.

Speaking at a forum of the Council on Foreign Relations, Banga said contributions could come from outside the World Bank's usual shareholder structure and regular contributions from countries to USAID funding for the poorest.

He noted that the contributions will include US President Joe Biden's proposed supplementary budget request of $2.25 billion for the World Bank, along with expected contributions from Germany, Japan, South Korea, Saudi Arabia and Scandinavia.

"I think if all of this comes true, including the United States, we can raise between $100 billion and $125 billion of additional lending capacity in the bank, which is kind of good. It's not enough, but it's good."

Such contributions could more than double the bank's move earlier this year to increase what's known as its leverage ratio to access an additional $50 billion in lending to help with climate change and other global development challenges.

Banga said he had not yet held any discussions with the United States and China on the general capital increase and changing the bank's shareholder structure.

China, India and Brazil took a larger share in the bank in the capital increase in 2018 and are likely to want to participate more in the capital increase in the future, he said.

Banga said China has been a "constructive partner" of the bank, as it cooperates in areas including climate, healthcare and rural development.