FRANKFURT—European Central Bank officials weighed the pros and cons of their bond-buying program at their latest policy meeting, and emphasised the program’s strict limits, according to a detailed account of the meeting could help to defuse a row with Germany’s top court.

The ECB scaled up its bond-buying program by €600bn to €1.35tn on 4 June, an unexpectedly bold move aimed at shielding the region’s businesses and governments during a deep economic downturn.