At its first policy meeting of 2016, the ECB held its key interest rates unchanged, as had been widely expected.
But Draghi said the central bank could review its monetary policy stance at its next meeting in March, immediately sparking a rally in stock markets and bringing down the euro.
"The decisions taken in early December ... Were fully appropriate," Draghi insisted, rejecting suggestions that they had been too timid.
"In this environment ... It will therefore be necessary to review and possibly reconsider our monetary policy stance at our next meeting in early March, when the new staff macroeconomic projections become available."
The ECB was "determined" to do everything in its power to steer eurozone inflation back up towards levels conducive to healthy economic growth, and there were "no limits" as to how far it is prepared to go in that respect, Draghi said.
A long series of policy moves by the ECB over the past 18 months -- ranging from interest rate cuts, the provision of unprecedented amounts of cheap liquidity and a controversial programme of bond purchases -- has failed to steer stubbornly low inflation back up to the target level of close to but just under 2.0 per cent.
Area-wide inflation stood at a meagre 0.2 per cent in December.
But "we are not surrendering," Draghi insisted.
At its last meeting in December, the ECB cut its key "deposit" rate by 0.10 percentage point to minus 0.30 per cent and extended the length of its asset purchase programme known as quantitative easing or QE by six months to March 2017.
Some ECB watchers argued that the tentativeness of the moves was an indication of divisions within the central bank's 25-member governing council regarding the need for more action, an interpretation apparently backed up by the minutes of the meeting, released earlier this month.
