Analysts have painted a grim picture of the consequences for the world's largest economy, with some warning that the impact could push the long-running eurozone debt crisis into the shade.
"The US fiscal cliff represents the single biggest near-term threat to a global economic recovery," the Fitch ratings agency said recently. "The dramatic fiscal tightening implied by the fiscal cliff could tip the US and possibly the global economy into recession. At the very least it would be likely to halve the rate of global growth in 2013."
The IMF has warned that even the uncertainty raised by the fiscal cliff has hit global investment and job creation. If the US actually fell off the cliff it could knock possibly four percentage points of growth off the US and undermine the fragile confidence in the rest of the world, it said.