By Takaya Yamaguchi and Tetsushi Kajimoto
TOKYO (Reuters) -Japan's top currency officials on Wednesday ramped up a warning against the yen's current weakness, saying the authorities would respond appropriately if moves become excessive, repeating similar comments by the finance minister on Tuesday.
Finance Minister Shunichi Suzuki said one-sided movements were seen in the yen's slide, which would warrant appropriate action by the Japanese authorities if the trend became excessive.
"It's important for currencies to move stably" reflecting economic fundamentals, Suzuki told reporters.
"We will respond appropriately to excessive currency moves if necessary," he added, but steered clear of specifying a particular currency level at which Tokyo would intervene.
Japanese policymakers argue that the deciding factor on intervention is the velocity of currency moves and not any specific level.
Nevertheless, investors are eyeing a 145-yen threshold for intervention, a level around which the government stepped into the market in September.
The Japanese currency fell 0.36% versus the greenback to as low as 144.02 overnight, its weakest since Nov. 10.
"We are closely watching currency moves with a strong sense of urgency," Japan's top currency diplomat Masato Kanda told reporters earlier on Wednesday. "We will respond appropriately if it becomes excessive."
Japan last conducted its rare yen-buying, dollar-selling intervention in September and October.