The foreign ministers of South Korea, China and Japan are likely to discuss the Chinese-led multinational lender as they are set to hold a three-way meeting in Seoul later this week, China's foreign ministry said Wednesday.

China launched the Asian Infrastructure Investment Bank (AIIB) in November with 21 nations in Asia and the Pacific region listed as its founding members. Close U.S. allies in the region -- South Korea, Australia and Japan -- have yet to make their decision.

The Chinese-led bank could be one of the agenda during the Saturday meeting in Seoul of the three foreign ministers -- Yun Byung-se from South Korea, Wang Yi from China and Fumio Kishida from Japan, China's foreign ministry spokesman Hong Lei said.

Asked whether the foreign ministers would discuss the issue of the AIIB, Hong replied, "They may touch upon this kind of issue."

"During the China-Japan-South Korea foreign ministers' meeting, foreign ministers of the three countries will exchange views on issues of common interest," Hong said.

Earlier in the day, a South Korean diplomatic source with direct knowledge of the matter said Seoul is "positively" considering joining the AIIB, raising the prospect for Seoul to join it despite Washington's opposition.

The end of March is the deadline set by China for all interested parties to join the new bank, which many experts see as a counterbalance to the Asian Development Bank and the World Bank, which have been dominated by the United States and other Western economies.

"We are in close communication with China's finance ministry with regard to a possible membership in the AIIB and are positively considering joining the AIIB," the source said on the condition of anonymity because no final decision has been made yet.

"From the perspective of our national interests, there is no reason for us not to join the AIIB," said the source.

Britain applied to join the AIIB last week, becoming the first major Western economy to seek membership in the Chinese-led bank.

Also this week, Germany, France and Italy followed Britain in seeking to take part in the AIIB.

The United States has been negative about the Chinese push that is seen widely as an attempt to bolster its economic clout in Asia.

The U.S. has called for transparency and high standards of governance as key requirements for such an institution.

China has offered US$50 billion with a reported stake of up to 50 percent in the AIIB, which South Korea viewed negatively because China could make a unilateral decision in the bank.

In Washington on Tuesday, the U.S. State Department said it is up to South Korea to decide whether to join the AIIB.

"It's a decision of any sovereign country, including South Korea, to make on AIIB," State Department spokeswoman Jen Psaki said at a regular press briefing.