European Central Bank chief Mario Draghi has said the bank will "review and possibly reconsider" monetary policy at its next meeting in March.
He said eurozone rates would "stay at present or lower levels for an extended period" and there would be "no limits" to action to reflate the eurozone.
His comments followed the ECB's regular meeting, where it kept the bank's benchmark rate unchanged at 0.05%.
The overnight deposit rate was also left unchanged at -0.3%.
At the ECB meeting in December, this rate had been cut from -0.2% in an attempt to push banks to lend instead of parking money at the ECB.
In December, the ECB had also extended its €60bn-a-month stimulus programme by six months to March 2017.
Eurozone inflation is currently running at 0.2%, way below the ECB's target of near 2%.
"We have the power, willingness and determination to act. There are no limits how far we are willing to deploy our policy instruments," Mr Draghi said.
Howard Archer, chief UK and European economist at IHS Global Insight, said "the stimulus trigger looks cocked and ready to pull as soon as the March ECB meeting".
'Risks'
Mr Draghi told a news conference: "As we start the new year, downside risks have increased again amid heightened uncertainty about emerging market economies' growth prospects, volatility in financial and commodity markets and geopolitical risks."
He said that could make it necessary to review - and possibly reconsider - monetary policy at the next meeting in early March.