The Bank of Japan should consider buying foreign bonds as part of efforts to reflate the economy during Gov. Haruhiko Kuroda's second term at the central bank helm, an economic adviser to Prime Minister Shinzo Abe said.

The BOJ is prohibited by law from buying foreign bonds for the explicit purpose of influencing currency rates, as exchange rate policy falls under the jurisdiction of the Finance Ministry.

But some academics have proposed that the BOJ could buy them if doing so was aimed at pump-priming the economy, an idea the central bank has dismissed so far because it would be hard to convince Tokyo's G-20 counterparts that Japan wasn't trying to weaken the yen.