Bank of Tokyo-Mitsubishi UFJ and Mizuho Corporate Bank have suspended transactions with Macau-based Banco Delta Asia SARL, designated by the United States as a major facilitator of North Korean money-laundering activities, sources said Thursday.

The transactions by the Japanese banks, which both have U.S. branches, were limited with Banco Delta Asia and the suspension has not affected customers, the banks said.

The Japanese Bankers Association urged its members in December to be cautious in dealing with the Macau bank.

The two major banks have suspended trade with Banco Delta Asia in line with the U.S. decision to ban banks under its jurisdiction from doing business with the Macau bank, government and Liberal Democratic Party sources said.

The U.S. Treasury Department in September alleged Banco Delta Asia was accepting large cash deposits from North Korean entities, including counterfeit dollars that it agreed to put in circulation, and imposed sanctions.

Bank of Tokyo-Mitsubishi merged with UFJ Bank in January to form Bank of Tokyo-Mitsubishi UFJ.