The European Council president Herman Van Rompuy said an October 17 meeting would take place a week later, to allow officials to "finalise" their plan.
But just hours later Mr Osborne said Europe needed to "come to a clear decision now".
"We need a comprehensive solution that puts our largest trading market on a much more stable footing," he said in a statement to the House of Commons.
The Chancellor also repeated his desire to see the package of measures completed by the time of the Cannes summit at the start of November.
And he said that eurozone nations must acknowledge that the 440bn euros in their rescue fund was not enough.
The delay to the eurozone meeting comes as new research warns the region is heading for a recession next year if leaders fail to manage the sovereign debt crisis.
Accountants Ernst & Young calculate that the combined GDP of the 17-nation group could fall by 2% next year and by a further 1% in 2013 if decisive action is not taken.
This would "almost certainly" drag the UK into recession as well, E&Y's Andy Baldwin told Sky News.
The firm's report claims that European leaders have vastly underestimated how much cash they need to contribute to the eurozone rescue fund and warn that bank lending in the region is already falling.
"The latest data already shows distinct indicators of recessionary risk," said E&Y economic advisor Marie Diron.
The warning comes a day after France and Germany said they had reached an agreement about how to strengthen the region's troubled banking sector amid the debt crisis.
A "comprehensive response" will be unveiled by the end of the month, including a detailed plan on how to recapitalise the banks, said the French President Nicolas Sarkozy.
"The economy needs secure financing to ensure growth," he added.
"There is no prospering economy without stable banks. That is what is at stake."
Mr Sarkozy and his German counterpart Angela Merkel refused to give further details of the plan, or an estimated cost, adding that other European leaders would need to see it first.
In Britain, the Prime Minister added to the calls for "decisive steps" from eurozone leaders.
David Cameron told the Financial Times: "You either make the eurozone work properly or you confront its potential failure."
