BY TAKASHI NAKAMICHI

TOKYO—The Bank of Japan is coming under renewed political pressure to take steps to weaken the yen, as the government seems to find itself constrained after being criticized by Washington for intervening in the currency market on its own to sell yen.

The administration of Prime Minister Yoshihiko Noda has been mindful of the risks that further meddling in the foreign-exchange market poses to the credibility of its economic policy.

But with the U.S. Federal Reserve's recently announced avowal of easy monetary policy causing the dollar to flirt with its record low against the yen, Japan's government is turning an ...