The nation's financial regulator is stepping up oversight of its biggest banks while stopping well short of imposing the type of intrusive stress tests that have been adopted in the U.S. and Europe.

Unlike the Federal Reserve and the Bank of England, which conduct annual examinations of the large banks they supervise, Japan's Financial Services Agency has no plans to impose its own stress tests on the country's lenders. Instead, it is looking for ways to verify the banks' own reviews.

"We're considering if we can come up with a stress test-like setup," Toshihide Endo, the director-general of the FSA's supervisory bureau, said in an interview last month. "We don't plan to impose external tests."