With the yen persistently weakening against the dollar ¡ª nearly hitting the ?164 mark ¡ª it would come as no surprise if Japanese authorities stepped in immediately to defend the currency.

Yet, because a standalone intervention is expected to be short-lived, the government is probably seeking effective timing ¡ª a moment when yen-buying pressure increases ¡ª to amplify its effect, according to some analysts.

One key factor is the policy path of the U.S. Federal Reserve, which will hold a policy meeting on Tuesday and Wednesday.