Japan’s financial regulator is urging local banks to better manage risks tied to their $655 billion (¥87.3 trillion) in securities holdings, even as they remain insulated from the recent turmoil at some U.S. peers.

"There is room for improvement in risk management at some banks,” said Tatsufumi Shibata, a senior official in charge of regional bank oversight at the Financial Services Agency.

"Their portfolios have been changing both in their makeup and importance,” he said in an interview, adding that it is necessary to put systems in place to deal with this.