Finance chiefs of the world’s 20 leading economies are ringing alarm bells over the U.S. fiscal cliff and Europe’s debt woes at a meeting in Mexico this weekend as they look to push back deficit reduction targets to help boost growth. Unless a fractious U.S. Congress can reach a deal, about $600 billion in government spending cuts and higher taxes are set to kick in on Jan. 1, threatening to push the American economy back into recession and hit world growth. But with the U.S. presidential election looming on Tuesday, dealing with the fiscal cliff has been delayed. “The Americans themselves acknowledge that this is a problem,” a G20 official said on condition of anonymity. “The U.S. administration says it doesn’t want to fall off the fiscal cliff, but right now it can’t tell us how exactly it will address it because that issue is on ice ahead of the election.”