The U.S. Treasury Department said it will press Japan to refrain from competitive devaluation while stopping short of accusing it of manipulating the yen, in a report on exchange rates.

The Treasury will pressure Tokyo to adhere to international commitments so as "to remain oriented toward meeting respective domestic objectives using domestic instruments, and to refrain from competitive devaluation and targeting its exchange rate for competitive purposes," the department said in its semiannual currency report to Congress that was released Friday.

The Bank of Japan surprised markets April 4 by doubling monthly bond purchases to almost match the U.S. Federal Reserve's monetary easing, and by setting a two-year horizon for achieving its goal of 2 percent inflation. BOJ Gov. Haruhiko Kuroda said Friday there's no time limit for the stimulus.