The United Nations' budget is set to shrink by over $285 million next year - a 5 percent cut that the US government says it negotiated, reports AP.

The UN General Assembly voted Sunday to approve the nearly $5.4 billion regular operating budget for 2018-2019. The Secretary-General's office says the new budget include cuts to most departments and offices.

The regular budget pays for many UN activities, but not peacekeeping or some humanitarian appeals, for example.

The U.S. is the largest contributor, paying about 25 percent of the regular budget. President Donald Trump has pressed to cut US contributions to the world body.

In a statement Sunday, US Ambassador Nikki Haley faulted the UN for "inefficiency and overspending" and said Washington won't let "the generosity of the American people be taken advantage of."