Reuters reports that ECB Chief Economist Philip Lane said that the ECB may not have the data it needs by its Sept. 9 meeting to decide the future of its emergency bond-buying programme.

The ECB last week decided to maintain an elevated level of bond buying, but as the economy rebounds and the pandemic retreats some policymakers are already making the case to start a discussion about rolling back emergency stimulus.

"We're not necessarily going to have every piece of hard data you want to have going into the September meeting," Lane told.

"September is of course going to be an important meeting, but there's going to be a lot of data coming in throughout the autumn," he said.

Lane also repeated the ECB's stance that, for now, it is "premature and unnecessary" to discuss questions related to the end of the bank's 1.85 trillion euro Pandemic Emergency Purchased Programme (PEPP), especially since unemployment remained too high and wage pressure was muted.