Some countries, however, might be granted time by the Commission in the coming months to bring their finances under control.
Rehn said as long as member states "have a credible medium term strategy for fiscal consolidation," then "it can make sense to take into account weaker growth to have more time for the fiscal adjustment."
Chris Williamson, economist with London-based Markit, welcomed the likely flexibility.
"This will clearly help to ease some of the political and social tensions that are apparent in the peripheral countries of Italy, Spain, Portugal and Greece," Williamson said.
Greece has faced the toughest hurdles and the Commission forecasts for the country show it's still got a struggle ahead.
The country is expected to shrink 4.4 percent this year — Greece's sixth year in recession — before posting growth of 0.6 percent in 2014.
One bright spot is that the Commission expects Greece to achieve a primary budget surplus — whereby revenues are higher than spending excluding interest payments — sometime this year. However, given the depth of its recession, Greece's debt burden will rise from 162 percent of annual GDP in 2012 to 175 percent this year and next.
Juergen Baetz can be reached on Twitter at http://www.twitter.com/jbaetz
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.