Lagarde said the risks surrounding the euro area growth outlook "remain tilted to the downside but less pronounced."

She cited encouraging signals including the news about the prospects for the global economy, the agreement on future EU-UK relations and the start of vaccination campaigns. Yet the ongoing pandemic and its implications for economic and financial conditions will be a source of the downside risks, she said.

The central bank president stressed that an important variant for the implementation of the PEPP is the so-called "favorable financing conditions," which would be assessed in a holistic approach, taken into account multiple indicators across all sectors, and also relative to the inflation dynamics.

Lagarde also reiterated the ECB's stance on the appreciation of the euro, which appeared to be a shared concern for journalists and analysts. "We will also continue to monitor developments in the exchange rate with regard to their possible implications for the medium-term inflation outlook," she said.

Meanwhile, a lot of attention has been given to the vaccine roll-out in Europe. Portugal's Prime Minister Antonio Costa told European parliamentarians on Wednesday that the vaccination campaign and economic and social recovery are the top priorities of the Portuguese Presidency of the Council of the EU.

While the roll-out of vaccines allows for greater confidence in the resolution of the COVID-19 health crisis, it will take time until widespread immunity is achieved, and further adverse developments related to the pandemic cannot be ruled out, Lagarde said on Thursday.

The EU in late December approved the use of two coronavirus vaccines. The European Commission on Tuesday called on member states to speed up the vaccination campaigns, with a target to inoculate 70 percent of the adult population by summer.

Meanwhile, 237 candidate vaccines are still being developed worldwide -- 64 of them in clinical trials -- in countries including Germany, China, Russia, Britain and the United States, according to information released by the World Health Organization on Jan. 15.