The world's leading economies pressed the United States and Europe to swiftly resolve their fiscal challenges on Monday, warning that they threaten to harm global growth. Finance ministers and central bankers from the Group of 20 leading developed and emerging nations vowed to do "everything necessary" to strengthen the world economy, reduce volatility in financial markets and generate jobs. The two-day talks in Mexico City focused on the eurozone's relentless debt crisis and the United States' looming "fiscal cliff" -- a set of automatic spending cuts and tax hikes in January that could impact global growth it they go in effect in January. "Global growth remains modest and downside risks are still elevated," the G20 said in a final communique. The statement cited "possible delays in the complex implementation of recent policy announcements in Europe" and a "potential sharp fiscal tightening in the United States." But the finance chiefs also voiced concern over Japan's own fiscal troubles as well as slowing growth in emerging nations and "additional supply shocks" in some commodity markets. G20 officials urged the winner of Tuesday's US presidential election, pitting incumbent Barack Obama against Republican Mitt Romney, to rapidly act to reach a deal with Congress after the vote. "The US leadership needs to address quickly the so-called 'fiscal cliff,'" said IMF Managing Director Christine Lagarde. She warned that there were "clearly factors of uncertainty not only for the US economy, but also for the global economy, given the size of the US economy." "Whoever is going to be elected or re-elected tomorrow will be faced with that challenge," Lagarde said. The G20 statement said Washington will "carefully calibrate" the pace of its fiscal tightening so that public finances are placed on a "sustainable long-run path while avoiding a sharp fiscal contraction" next year. Spanish Economy Minister Luis de Guindos warned that the US fiscal cliff hung over the world like a "sword of Damocles." "What happens tomorrow in the presidential and legislative elections in the United States will be crucial," he said. "For this reason the US delegation could not be very categorical." US Treasury Secretary Timothy Geithner sent a deputy to the G20 talks, as did other key G20 policymakers, including European Central Bank president Mario Draghi and the finance ministers of France and Brazil. Since a G20 summit in June, the IMF slashed its 2012 global growth forecast to 3.3 percent, eurozone unemployment rose to a record 11.6 percent in September and growth decelerated in emerging nations. In light of weaker growth, G20 nations reaffirmed their commitment to reduce public deficits but gave themselves more room for maneuver, saying "they will ensure that the pace of fiscal consolidation is appropriate to support the recovery." Europe's debt crisis was again in the spotlight at the G20 talks. "There was a clear message from many in the room today to our European colleagues that they do need to remove the policy uncertainties that are dragging on growth and investment," said Australian Treasurer Wayne Swan. But the eurozone also won praise for recent moves to create a banking union, activate a 500-billion-euro ($650 billion) crisis firewall and launch a European Central Bank bond-buying program. While G20 nations "recognize" the progress made in Europe, "there is also impatience and a strong demand for all of this to be put in place in an effective and concrete way," a senior G20 official said. Greece faces key deadlines to avoid bankruptcy this month, while Spain is under pressure to seek a bailout of its own amid a recession that has pushed the unemployment rate to 25 per cent. De Guindos outlined his country's banking and labor reforms to G20 counterparts at a dinner Sunday night. But he told reporters Monday that his country does not need a rescue from European partners for now as it was "well-financed this year." Greece, meanwhile, is in tough negotiations with the European Union, the International Monetary Fund and the European Central Bank to unlock a 31.5-billion-euro tranche of a bailout package or risk bankruptcy this month. The Greek parliament will hold crucial votes this week on a new round of austerity demanded by international lenders. But Greece also wants a two-year delay to implement its fiscal obligations, an issue that divides Europeans. EU Economic Affairs Commissioner Olli Rehn said the eurozone was "on track" to take a decision on the bailout funds at a November 12 meeting of finance ministers.