The ECB said this month it could still extend its 2.55 trillion euro ($3.17 trillion) bond purchase scheme beyond September if needed. But it skipped a reference to bigger purchases, a signal that it remains on track to end a three-year-old stimulus scheme before the end of 2018.
"This purchase programme runs until the end of September 2018. We will have to decide in summer what happens next," Nowotny, who as governor of the Austrian National Bank sits on the ECB's Governing Council, told a news conference.
"And I think that if we have a situation like the one we now expect ... that we will have the possibility to reduce this programme significantly and head towards an end of the programme," he added
Asked what lessons he drew from the US Federal Reserve's earlier cutting of bond purchases and raising of interest rates, he said: "One is to act when it is necessary ... to avoid being behind the curve.
"So, to wait too long is problematic. But another is to approach steps very cautiously and communicate in time."