Whoever wins November's presidential elections must make dealing with a fast-approaching fiscal cliff a top priority and follow up with long-term reforms to taxes and spending, said Carlyle Group co-founder David Rubenstein.

At the end of this year, tax cuts expire at the same time cuts to government spending kick in, a combination known as a fiscal cliff that could send the country sliding into a recession next year if left unaddressed by Congress.

Lawmakers won't likely tackle the fiscal cliff in an election year, but after elections, the new president must find a way to steer the country away from the sudden fiscal adjustment that could siphon hundreds of billions of dollars out of the economy next year alone.

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.

Long-term fiscal imbalances must take priority as well.

"The most important thing the next president has to do is resolve the uncertainty of the debt and deficit,” Rubenstein said, according to CNBC.

Other noted financiers agree.

“We have to get our budget on a sustainable path where it’s predictable,” said Goldman Sachs CEO Lloyd Blankfein, CNBC added.

“What we really need to do is fix the U.S. economy on a sustainable basis so there’s some predictability, so people don’t stand on the sidelines and so they go and invest and jobs get created.”

Even if Congress lets January 1 come and go without dealing with the fiscal cliff but successfully addresses it retroactively afterwards or find other ways to delay the event, businesses will hold off on expanding and hiring, uncertain of what they'll be paying in taxes.

Such uncertainty is hampering recovery in the U.S., which in turn is hurting the global economy.

"Growth would stall in 2013 with the full materialization of the cliff and... would inflict large spillovers on major U.S. trading partners and also on commodity exporters," the International Monetary Fund said in its World Economic Outlook.

"The urgent policy priorities in the United States are to avoid excessive fiscal contraction in the short term, promptly raise the debt ceiling, and agree on a credible fiscal consolidation plan —centered around entitlement and tax reforms — that places government debt on a sustainable path in the medium term," the multilateral lending institution added.

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.