RIGA, Latvia — The European Central Bank took a major step on Thursday toward winding down life support for the eurozone economy.

Meeting in Riga, the Latvian capital, the central bank’s Governing Council said it would slow its purchases of government and corporate bonds in September, and then end the program entirely at the end of the year. The stimulus was essentially a form of money printing known as quantitative easing that helped prevent the eurozone from collapsing under the strain of a debt crisis.

The bank said it did not expect to raise interest rates, which are at historic lows, until the fall of 2019 at the earliest. Mario Draghi, the central bank’s president, also held out the possibility that policymakers could still ramp up stimulus if needed.

The bank had not been expected to lay out so clearly its road map for the months ahead. The mere fact that the topic of reducing the stimulus program was on the agenda was significant.