FRANKFURT — Top officials of the European Central Bank sent strong signals on Wednesday that action to stimulate the economy was all but certain next month. But they also made it clear that the bank was unlikely to make a powerful injection of money into the economy.

Such a boost, which the Federal Reserve accomplished in the United States through huge purchases of government bonds, is seen by many analysts as necessary to prevent the euro zone from tipping into a new crisis.

At its meeting in June, the E.C.B. is likely to cut the main interest rate to close to zero, begin penalizing banks for hoarding cash by means of negative interest rates and perhaps issue a new round of cheap loans to banks, according to the comments by the central bankers. The E.C.B. could also buy assets like packages of bank loans.

Expectations were already high that the bank would do something at its June 5 meeting to promote growth. Mario Draghi, the president of the bank, said last week that there was a consensus on the bank’s 24-member governing council that inflation was too low and that something should be done about it.