North Korea has expressed interest in the Chinese-led Asian Infrastructure Investment Bank, but failed to apply for membership, a diplomatic source said Monday.

South Korea and 56 other economies became founding members of the AIIB, which is seen as a potential counterbalance to U.S.-led multilateral lenders such as the Asian Development Bank and the World Bank.

"To my knowledge, North Korea had expressed interest in joining the AIIB and looked into ways to take part in it through an unofficial channel," the source said on the condition of anonymity.

Last month, British financial news website Emerging Markets reported that China refused the entry of North Korea to the AIIB because Pyongyang failed to provide data on its economy.

On March 31, China's foreign ministry spokeswoman Hua Chunying said she was "not aware" of any reported snub of North Korea.

The founding members of the AIIB will hold their fourth meeting in Beijing next Monday and Tuesday to discuss the bank's governance and voting rights.

They will hold another round of meetings in Singapore next month before signing the final "Articles of Agreement" for the AIIB in June.

China has offered $50 billion to the bank, which is expected to start operations by the end of this year, with other member countries expecting to increase the total funding to $100 billion.

The state-run China Daily reported last week that the AIIB's Asian members could have 75 percent of the voting rights, while the remaining 25 percent would go to non-Asian members.

Russia, which is a part of the World Bank and the ADB as a European member, has joined the AIIB as an Asian member.

"One of interesting points is how China and Russia would share their voting rights within the Asian membership category of the AIIB," the source said.

The U.S. has expressed concerns over the transparency of the Chinese-led bank's governance and decision-making process. (Yonhap)