The Group of 20 economic powers will urge members to take decisions to reduce economic uncertainty when policymakers meet early next month, Mexican Deputy Finance Minister Gerardo Rodriguez said on Friday.
Mexico will host finance ministers and central bankers from the bloc of advanced and developing countries next weekend.
Rodriguez told reporters that uncertainty was costing jobs and putting pressure on global growth.
Asked if struggling Spain should seek financial aid, he said it was up to countries to take their own decisions but that in general, firewalls had to be used for them to be effective.
Spain is under pressure to seek a bailout as it struggles to cope with high government debt and the cost of recapitalizing its banks. Euro zone sources said they expected Spain to seek financial aid from the euro zone in November.
Rodriguez said Spain would give an update on progress on stabilizing its economy at the G20 meeting.
World finance leaders met just two weeks ago in Tokyo, where they urged Europe and the United States to tackle debt which threatens to stifle global growth.
The International Monetary Fund cut its forecast for global growth to 3.6 percent for 2013 and urged the United States to take steps to avoid a year-end 'fiscal cliff' of tax hikes and spending cuts that would tip it back into recession.
Rodriguez said that markets were so far giving the United States the benefit of the doubt on the fiscal cliff but that the G20 was still assessing the situation.
He added that foreign exchange flexibility remained an important subject for the G20.
(Reporting by Krista Hughes; Editing by James Dalgleish)