Fitch on Monday cut its credit rating on heavily indebted Japan by one notch, warning that Tokyo had not done enough to plug a budget gap left by its decision to delay a sales tax rise.

The move saw Japan's rating trimmed to "A" from "A+" and comes several months after rival credit agency Moody's also downgraded Japan's credit rating, citing "rising uncertainty" over the debt situation and Prime Minister Shinzo Abe's faltering efforts to kickstart the world's number three economy.