Japan's government wants to act if "rapid, one-sided" moves seen in the currency market recently continue, the country's top government spokesperson warned on Wednesday as the yen slid to a fresh 24-year low.

The comments marked officials' latest verbal warning against the fall of the yen, which weakened beyond 144 yen per U.S. dollar after slumping about 1.5 percent on Tuesday.

"I'm concerned about rapid, one-sided moves in the currency market recently," Chief Cabinet Secretary Hirokazu Matsuno told reporters at a news briefing, using stronger language about the yen's fall than officials' remarks earlier this week.

The government "would like to take necessary steps if such movements continue," he said, adding that sharp fluctuations were not desirable. He made the comments before the yen hit a fresh low.

Such official remarks, called "jawboning" in foreign exchange markets, are intended to make traders cautious by implying the authorities may intervene.

Japan last intervened by selling the dollar and buying the yen in the forex market in June 1998 when the yen fell beyond 146 per dollar.

The Japanese currency, which dropped as low as 144.38 per dollar on Wednesday, has lost about 20 percent since the start of the year, driven lower mainly by divergence in monetary policy between Japan and the United States.

(Source: Reuters with edits)