Haley said the plan calls for a $285 million cut for the 2018-19 fiscal year.
"The inefficiency and overspending of the United Nations are well known. We will no longer let the generosity of the American people be taken advantage of or remain unchecked," Fox News quoted Haley as saying.
The U.N. budget now covers a two-year period, beginning in January of an even-numbered year.
Haley added, "This historic reduction in spending - in addition to many other moves toward a more efficient and accountable U.N. - is a big step in the right direction."
The U.S. pays about 22 percent of the U.N.'s budget, or roughly 3.3 billion dollars, and fully 28 percent of its peacekeeping effort.
Earlier, President Donald Trump had also threatened to cut off financial aid to countries that vote in favour of the U.N. draft resolution.
The US has vetoed an Egyptian-drafted UN Security Council resolution that called on countries not to establish diplomatic missions in Jerusalem.
The final tally was 128-9, with 35 nations abstaining, including five members of the European Union. (ANI)