Saudi Arabia, the world's largest crude oil exporter, may exhaust its financial assets – required to continue spending – over the next five years, if the government does not change its current policies in the wake of falling oil prices, according to the International Monetary Fund (IMF).

IMF stressed the need for immediate steps to bring down its budget deficit.

Bahrain and Oman, members of the six-member Gulf Cooperation Council, are facing a similar situation, it said.

On the other hand, Kuwait, Qatar and the United Arab Emirates are well-positioned with financial assets that could support their spending for over 20 years, the Washington-based lender said.

Saudi government is already mulling to cut spending in order to improve its public finances, but the IMF said "measures being considered by oil exporters are likely to be inadequate to achieve the needed medium-term fiscal consolidation."

"Under current policies, countries would run out of buffers in less than five years because of large fiscal deficits," Bloomberg quoted IMF as saying.

A plunge in crude oil prices in recent months due to oversupply issues is forcing the kingdom to postpone projects and resort to bond sale, its first since 2007. Its net foreign assets declined to more than two-year low of $654.5 billion in August. Saudi Arabia derives nearly 80% of its income from oil exports.

The IMF estimates Saudi's budget deficit to increase to over 20% of its gross domestic product (GDP) this year, largely led by King Salman's announcement of "one-time bonuses for public-sector employees" after his accession to the throne in January.

"The budget deficit in Saudi Arabia does go down substantially as a share of GDP over the next five years but it still remains high over this period, all the more reason to identify ways in which it can be brought down further to more a manageable level," said Masood Ahmed, director of the Middle East and Central Asia department at the IMF.

Saudi Arabia had opposed the idea of cutting oil output fearing loss of market share, even as other countries in the oil cartel, the Organization of Petroleum Exporting Countries (OPEC), lobbied for production cut.