United Nations Secretary General Antonio Guterres revealed the dire state of the organization's finances —which he described as "severe"— in a speech made on Tuesday.

He announced that the UN are "exhausting" peacekeeping cash reserves and warned that the organization may not be able to pay some staff next month.

The announcement comes after the US, the largest contributor to the UN, drastically cut funding to the organization this year.

According to a report from CNN, the US currently owes the UN around $1 billion in unpaid contributions.

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United Nations Secretary General Antonio Guterres said that the organization may not have enough funds to pay staff salaries next month as it is dealing with its worst funding deficit in a decade, made worse by an outstanding bill of $1 billion in unpaid US dues, according to a report from CNN.

Guterres revealed the dire financial situation of the UN during his speech on Tuesday.

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United Nations General Assembly at U.N. Headquarters in New York City. Andrew Renneisen/Getty Images

The Secretary General detailed the proposed budget for 2020, before going on to outline how the UN is "facing a severe financial crisis."

"This month, we will reach the deepest deficit of the decade," he said.

"We risk exhausting the closed peacekeeping cash reserves, and entering November without enough cash to cover payrolls."

The funding shortfall is being blamed on many UN member states failing to pay the organization their outstanding dues — basically membership fees — for 2019. 64 of 193 member states have yet to pay their full dues for the year, with the US the worst offender, according to CNN.

CNN reported that the US is due to contribute $674 million to the UN budget this year, but because of underpayments in previous years, owes the organization over $1 billion, according to the UN spokesman's office. The US tends to pay its UN dues towards the end of the year, CNN added.

"The Secretariat could face a default on salaries and payments for goods and services by the end of November unless more Member States pay their budget dues in full," Stéphane Dujarric, Guterres' spokeman said.

United Nations Secretary General Antonio Guterres addresses the opening of the 74th session of the United Nations General Assembly at U.N. headquarters in New York City, New York, U.S. Reuters

The US administration announced in 2017 that it would reduce funding to the UN and other agencies run by the UN.

The US is the largest financial contributor to the UN, followed by the United Kingdom and Germany. This year it is expected to contribute around 22% of the UN's total budget, CNN reported.

In 2017, the US negotiated a cut of around $285 million to the UN's $5.5 billion budget for the 2018-19 financial year, Nikki Haley, who was the US ambassador to the UN at the time said, according to CNN.

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Guterres also detailed the enforcement of "extraordinary measures" in order to cope with the shortage of cash.

These measures include limited travel for employees, the deferral or cancellation of meetings, and cutting back hours of support from staff.

He also announced that the UN will not be filling empty vacancies in this period and urged all member states of the UN to adhere to their financial obligations "on time and in full."