The 25-member Governing Council kept its main refinancing rate or the price that banks pay to borrow funds from the ECB, unchanged at 0.05 percent
"We are confident that the decisions are adequate to achieve our objective. The deposit rate cut vastly improves policy transmission," Draghi said, adding that the ECB has a "menu of options" for the asset purchase program and the parameters of the plan will be reviewed again in spring next year.
Analysts suggested Draghi offered markets the "bare minimum of easing", resulting in the sell-off seen in stocks.
"First, he hasn't quite pushed out the 'boat on QE2'! By extending it six months to March 2017, and including regional and local debt, his sign of intent is he will do more. But, by not upping the pace, at just 60 billion euro purchases per month, and excluding other assets such as more corporate bonds and mortgage debt, he is keeping some powder dry," said group chief economist at Hermes Investment Management, Neil Williams.