(Bloomberg) Saudi Arabia can’t afford to wait for oil prices to recover and needs to accelerate economic measures to avoid rising unemployment, deficits and debt, McKinsey & Co. Inc. said in a report released Thursday.

The country requires public and private investments of as much as $4 trillion as part of a strategy to boost productivity and create jobs, the report said. Based on current trends, Saudi Arabia “could face a rapid economic deterioration over the next 15 years.” Even a public spending freeze and halt to hiring foreign workers would still leave the country facing falling household incomes, rising unemployment and weakening finances.

“This is a call to dramatically accelerate reforms which ultimately will provide a more sustainable future,” Jonathan Woetzel, a McKinsey Global Institute director and main author of the report said by phone. “Waiting for the world to get better is not an option.”

A slump in crude prices, the government’s main source of revenue, is pushing the world’s biggest oil exporter into its first deficit since 2009 and its foreign reserves to a three year low. The International Monetary Fund predicts that Saudi’s savings, $640 billion at the end of October, would run out after five-years under current spending policies. In response, the government is planning to cut spending on infrastructure projects, and tapping debt markets to fund the deficit.