As of end-March, the three banks had total credit exposure of about $64 billion to China, or roughly 1% of their total assets, according to their financial statements.
The FSA's request to look into China-related geopolitical risk was made in May, said two other sources.
At a meeting last month, one of the banks was asked by the FSA how it is assessing risk related to China operations, one of them said.
China claims democratically governed Taiwan as its territory and has never renounced the use of force to bring it under its control.
Dealing with China sanctions would be extremely complex, the executive added.
Persons:
Banks, SMFG, Antony Blinken, Wang Yi, Takaya Yamaguchi, Makiko Yamazaki, Sumeet Chatterjee, Jamie Freed
Organizations:
Financial Services, Mitsubishi UFJ Financial, Sumitomo Mitsui Financial Group, Mizuho Financial Group, Mizuho, American Chamber of Commerce, Reuters, Thomson
Locations:
China, TOKYO, Ukraine, Russia, United States, China . U.S, Beijing, West, Taiwan, U.S, Tokyo, New York