The euro zone is under pressure from its G20 partners to unveil a convincing plan at this summit to address the bloc's debt crisis and prevent the world economy from falling back into recession."Any decision should be enforced immediately, concerning the strengthening of the EFSF or concerning increased guarantees for our banks," Barroso told French LCI television.Barroso, who was speaking after meeting with French President Nicolas Sarkozy in Paris, insisted a review of the second Greek bailout package decided on July 21 was necessary but it should retain the voluntary involvement of banks and not trigger a credit event."We have to recognise that we'll need to review some of the parameters of July 21 ... But it is essential to have a voluntary mechanism and to prevent any Greek default," he said.According to sources, the two heavyweights of the euro zone, France and Germany, disagree on the scope of this review, with Berlin pushing for a bigger reduction of Athens' debt pile and for a larger contribution of private investors than the one initially foreseen.The two countries agreed last Sunday that European banks should be recapitalised. A decision is expected on Oct. 23 on how much money will be needed but Barroso declined to comment on any figure.He said some countries in Europe should sustain economic activity by using fiscal stimulus, echoing a similar call in September by U.S. Treasury Secretary Timothy Geithner which was then opposed by Germany, one of the few countries in the euro zone with such leeway."Countries with room for manoeuvre should boost growth", Barroso said.