Silence seems golden for the government, which wants to leave investors guessing whether Tokyo will intervene in the foreign exchange market to stem the rise of the yen against other major currencies.

Finance Minister Jun Azumi repeatedly said "No comment" last week in dodging questions from reporters about the government's position on the Japanese currency's resurgence against the dollar and the euro amid uncertainty over the sovereign debt crisis in Europe.

Azumi had previously been rather candid in warning against speculators chasing short-term profits with large one-sided bets at times of market instability, saying Japanese monetary authorities will respond "decisively" if necessary — a code word suggesting readiness to intervene and counter any disorderly movement in the yen's rates due to such investors.