The city-state - which has closed its borders to try and stem a coronavirus outbreak that is expected to push its economy into recession this year - usually releases its semi-annual policy statements in April and October.
First quarter preliminary growth figures will also be released earlier than expected on Thursday, when the finance minister is due to unveil new measures to help firms and households weather the economic impact from the pandemic.
The Singapore dollar fell sharply to more than a 10-year low against the U.S. dollar after the announcement. Earlier on Monday, data showed Singapore's main price gauge slipped into deflation for the first time in over a decade.
All nine economists in a Reuters survey last week said they expect the Monetary Authority of Singapore (MAS) to ease by changing the Singapore dollar's pace of appreciation to a neutral "zero slope". The MAS manages policy through its currency rather than interest rates.
Five said it may take more drastic action by re-centering down the mid-point of the policy band in which the currency is allowed to trade - a move taken a decade ago during the global financial crisis.
(Reporting by John Geddie and Tom Westbrook; Editing by Jacqueline Wong)
