Euro-zone countries should prepare to implement more measures aimed at cutting "excessive deficits" if economic growth disappoints, the European Central Bank said.

The 16 members of the euro-zone should "be prepared to accelerate consolidation where necessary to correct their excessive deficits," the ECB said, according to The Wall Street Journal. "If previously overly optimistic macroeconomic forecasts fail to materialize, countries should swiftly adopt additional consolidation measures to ensure that commitments are fulfilled."

Euro-zone countries are theoretically held to rules in the Maastricht Treaty that stipulate that a country's deficit shouldn't grow by more than 3% of GDP a year. Member countries have repeatedly violated this rule.

Higher-than-expected growth in the first half of the year should help countries reduce their debt burden, the ECB said. Still, countries like Ireland won't meet the required deficit limit before 2014, the bank said.