The leaders of the world's biggest economies hope to restore global growth by the end of 2010, the Financial Timesreported, quoting a draft communique for a summit this week.
US President Barack Obama told the newspaper he saw signs that the slump was stabilizing.
Stimulus measures already taken will raise global output by more than 2 percentage points and create more than 20 million jobs worldwide, the FT said, quoting from the draft ahead of the summit of G20 leaders in London on Thursday.
As well as higher spending, leaders are pinning their hopes on measures to save their banks and more money for the International Monetary Fund to stem the worst global economic crisis since the 1930s.
The G20 leaders will discuss ways of fighting the crisis, including new, tighter rules for financial institutions aimed at preventing a repeat of the credit crisis and help for international trade.
The draft appears to contain no specific numbers on further government stimulus measures aimed at boosting demand, an area of disagreement between Washington and some European countries which have favoured more emphasis on regulatory reform.
The United States has pressed for more effort from other countries but mainland Europe says it has done enough for now.
Obama told the FT in an interview that G20 countries would agree to "do what is necessary to promote trade and growth" and he played down talk of a transatlantic rift.
“The most important task for all of us is to deliver a strong message of unity in the face of the crisis,” Mr Obama told the newspaper in the interview published on the FT's website.
The president said he saw “glimmers of stabilization” including signs that the US housing market - the source of the global slump - was stabilizing.
With governments around the world setting aside trillions of dollars to save their banks and boost their economies, Obama conceded public opinion in the United States and elsewhere might make it hard to come up with further measures.
But it was also important “that we are prepared to step into the breach should current efforts prove to be inadequate.”
British Finance Minister Alistair Darling said countries would not be asked to reveal their spending plans at the summit but they should realize boosting demand will play a key role in any recovery.
“We are not saying that everybody has got to do the same thing, at the same time, on the same day,” he told the BBC. “We do need to ... make sure we have a commitment for countries to act together, to do what is appropriate in their countries”.
Reuters