UPDATE 1-Japan's top FX diplomat Kanda says cannot overlook 'speculative' yen moves

(Adds quotes)

By Satoshi Sugiyama and Takaya Yamaguchi

TOKYO, April 29 (Reuters) - Japan's top currency diplomat, Masato Kanda, said on Monday current developments in the exchange-rate market were "speculative, rapid and abnormal", and that they could not be overlooked.

Kanda declined to comment when asked by reporters whether authorities intervened in the currency market on Monday to prop up the yen.

But he described the yen's declines since late last week as "excessive volatility driven by speculative trading," suggesting that the moves justified intervening in the currency market.

"The developments we're seeing now ... can be described as speculative, rapid and abnormal volatility. The damage such moves inflicts on the economy is hard to overlook," Kanda said.

"As such, we hope to continue taking appropriate action as needed," said Kanda who, as vice finance minister for international affairs, oversees Japan's currency policy.

Kanda also said authorities were ready to act "24 hours, 365 days," when asked about the chance of intervening in the currency market. (Reporting by Satoshi Sugiyama, Tetsushi Kajimoto, Takaya Yamaguchi, Yoshifumi Takemoto and Takahiko Wada; Writing by Leika Kihara; Editing by Chang-Ran Kim and Mark Potter)