The United States has long contributed the most to the United Nations regular budget -- but has the US been paying too much? Well, it's complicated.
On the one hand, the US is paying (a lot) more than any other country on the planet to the UN's regular budget. But it's still paying less than you might expect based on the massive US economy, which accounts for a quarter of the world's gross income.
Still, China is paying way less than you'd expect given its gross national income. But when you factor in goods that some other countries are giving to the UN, plus UN criteria that look at each nation's economy per person, the US number might not look like such a crazy share of the total pot, after all.
Here's a deeper look at how much nations around the globe are footing the bill for the United Nations -- and you can judge for yourself.
Is the US paying its fair share?
The United Nations uses a rubric to determine how much member states contribute to its regular budget based on "gross national income" -- which is basically a trumped-up version of gross domestic product that includes salaries and taxes from overseas.
The good news for the US? The UN caps the maximum contribution at 22%.
The US makes up a quarter of the world's gross income, according to the Organisation for Economic Co-operation and Development and the World Bank, but hits the maximum cap under UN rules, so it only foots the bill for only 22% of the UN regular budget.
But some other comparable states? They're paying a lot less. China covers 14% of the world's total income but pays only 8% of the UN budget.
Other countries like Canada, Germany and the United Kingdom are within a percentage point or two of what you'd expect them to pay based on this metric. Russia accounts for 2% of the world's income but pays for 3% of the UN budget. India accounts for 2% of income around the globe but pays less than 1% of the UN budget.
But it's not quite that simple
The UN uses a handful of other measurements to determine how much states should pay to the regular budget. One big factor is looking at that gross national income stat -- per capita.
The US has one of the highest income per capita numbers in the world at $58,656 per person, according to the latest numbers from the OECD. Japan and the United Kingdom have numbers that at least fall in the same ballpark, at $42,279 and $42,143, respectively. But Russia's comes down at $22,609 and China's falls to just $14,329 per person.
The UN also tweaks its final numbers based on the amount of debt the country has.
But the US hasn't been following the trends of other nations
Over the last two decades, data from the UN show that Western nations like France, Germany, Japan and the UK have seen their proportion of the UN budget slashed over time. Countries like China and Russia have seen their responsibilities increase.
But the US hasn't seen a change in payment since 2001, when the maximum contribution cap was cut from 25% to 22% -- the slice of the UN regular budget that the US has footed every year since then.
Yup, it gets more complicated
It's important to note that the UN's regular budget is really only a piece of what countries end up contributing to the organization. Other countries contribute more in goods like food, clothing and fuel to other satellite organizations tied to the UN.
The US also pays a significant part of UN peacekeeping missions. "We also ask that every peacekeeping mission have clearly defined goals and metrics for evaluating success," Trump said Monday.
But when you look at all of the goods and services that come from other countries, the US actually makes up less than 9% of these goods and services. India -- which contributes very little to the regular budget itself -- pays more than 6%. Belgium and the United Arab Emirates pay 5% each, Denmark pays 4%. Turkey, France and the United Kingdom pay 3%.
These countries give everything from food to clothing and footwear to fuel to shelter and construction supplies to other administrative services for UN agencies, according to the United Nations Office for Project Services, which tracks the contributions to more than three dozen UN-related organizations.
Correction: This article has been corrected to substitute a different form of gross national income numbers used by the UN to determine member payments.