The United States on Thursday withheld comment on South Korea's decision to join the Chinese-led regional development bank AIIB, only expressing hope that members will work toward having the institution embrace transparency and high standards.

"I am not going to react or comment on their decision. I would say in general we've seen a number of countries make decisions to join the bank. That is their decision," State Department spokesman Jeff Rathke said at a regular press briefing.

"We certainly hope that as we stress the importance of international standards and transparency, that there will also be voices for them saying those same values," he said.

South Korea's decision has been expected since Britain, France and other European countries joined the bank that has been seen as a Chinese effort to bolster its economic clout by creating a counterbalance to the Asia Development Bank led by the United States.

Rathke said the U.S. agrees on the need to enhance infrastructure investment around the world, and would welcome multilateral institutions that strengthen the international financial architecture and incorporate the "high standards that the international community has collectively built."

"We encourage the Asia Infrastructure Investment Bank to follow those high standards, but the United States has not decided to joint the bank. We have concerns about those standards and transparency as we outlined in great detail from here," he said. (Yonhap)