China's official Xinhua news agency suggested in an editorial that the United States might be embarrassed that many of its allies had not heeded its warnings.

"Decision-makers in the United States really have to be reminded that if they do not jump on the bandwagon of change in time, they will soon be overrun by the bandwagon itself," it said.

IMF Managing Director Christine Lagarde said the fund would be "delighted" to cooperate with the AIIB.

China's Lou and ADB President Takehiko Nakao said at the conference they had held discussions on possible cooperation, with the Chinese finance minister adding that topics discussed included safeguard standards.

Lou has previously said AIIB would complement rather than compete with other institutions such as the ADB, the Manila-based multilateral lender dominated by Japan and the United States.

The AIIB's Jin said developing countries in Asia would receive the bulk of loans for infrastructure projects, which could be co-provided with commercial banks and pension funds.

Non-Asian countries would also only hold 25 percent of the AIIB's shareholding, lower than their stakes at the founding of the ADB, he said.