Japanese Finance Minister Shunichi Suzuki said on Tuesday that any decision on currency market intervention would be based on volatility, not specific yen levels, as investors brace for a possible move if the yen breaches the 150-per-dollar threshold.

Authorities are watching the currency market closely and stand ready to respond, Suzuki said, repeating a warning against speculative moves as the yen hovered near a one-year low versus the dollar, just shy of the 150 mark.

"Currency levels won't be a factor for judgment" on whether to intervene, Suzuki said. "It's volatility that matters."

The foreign exchange market showed little reaction to Suzuki's comments, although traders have been on watch for action by the Japanese authorities with the yean near levels that prompted intervention a year ago.

Speaking at a regularly scheduled press conference, Suzuki also said the authorities were watching market moves with a high sense of urgency.

"It was important for currencies to move stably, reflecting economic fundamentals," Suzuki told reporters. "We will be fully prepared to respond with a high sense of urgency."

A weak yen boosts prices by raising the cost of imports, Suzuki said, adding that other factors also affect cost-driven inflation, including the war in Ukraine and cuts in output by oil-producing nations.

As for newly issued 10-year government bonds that carry a yield of 0.8%, a decade-high level, Suzuki said long-term interest rates are set by the market, reflecting various factors.

Suzuki said that, generally speaking, rises in long-term rates push up borrowing costs, and authorities are therefore closely watching the impact of moves in long-term rates and how they may affect households and businesses. (Reporting by Tetsushi Kajimoto and Kantaro Komiya; Editing by Chang-Ran Kim and Edmund Klamann)