The accounts were set up in Mongolia, Russia and Vietnam, among other countries, the Sankei Shimbun newspaper said, citing an unnamed source familiar with North Korean matters.

The United States, concerned that the new bank accounts may be used for transactions related to weapons proliferation or other criminal activity, has asked authorities in those countries to freeze the accounts, the paper said.

North Korea allegedly opened the accounts after the United States last year banned US financial institutions from dealing with Banco Delta Asia (BDA), which it suspects of being a willing front for laundering money for Pyongyang.

Last month, a South Korean lawmaker said the Bank of China had frozen all North Korean accounts after US financial investigators reportedly discovered fake US dollar bills at its branch in Macau.