Mario Draghi, president of the European Central Bank.

European Central Bank policymakers are concerned that economic growth in the euro zone is even weaker than feared, eroding their confidence in a long-projected recovery in the second half of the year, the accounts of their April 10 meeting showed on Thursday.

With growth unexpectedly weak for months now, the ECB has raised the prospect of more support for the economy but argued that more analysis was needed to see if the rapid loss of economic momentum is persistent or temporary.