The Bank of Japan still has policy options to continue its unprecedented monetary easing, Chief Cabinet Secretary Yoshihide Suga said in an interview days after the central bank announced it would not expand its main stimulus target.

"I think they still have policies they can pursue," Suga said Wednesday at his offices in Tokyo when asked about concerns the program could be reaching its limits. "I am not at all pessimistic about this."

Suga, Prime Minister Shinzo Abe's top aide, said the central bank should continue efforts to achieve its 2 percent inflation target, and that there is no need to change the law to increase political control over the BOJ, as has been suggested by some lawmakers.