Foreign currency interventions, when conducted unannounced, are designed to maximize the effect of correcting rapid currency moves and such operations are effective “to a certain degree,” Finance Minister Shunichi Suzuki said Tuesday. Suzuki reiterated Japan will take appropriate action to address excessive volatility in the currency market by keeping close tabs on developments with a high sense of urgency. His remarks came as the U.S. Federal Reserve is expected to go ahead with another rate hike at its policy meeting this week, a decision that would widen the interest rate differential betwe…