The claim: The US has the highest taxes in the world.
Reality Check verdict: The total amount of tax raised by the United States as a proportion of the size of its economy is not the highest in the world. It also does not have the highest rates of taxes on households. By one measure, it does have the highest rate of corporation tax.
A broad measure of the level of taxes is to look at the total amount of tax taken by the government as a percentage of the amount produced by the economy (GDP).
The US is clearly not at the top of this list based on figures from the Organisation for Economic Co-operation and Development (OECD).
In 2015, the US tax take came in at 26.4% of GDP, well below countries such as Italy at 43.3%, France at 45.5% and Denmark at 46.6%.
So, for overall tax, the US is certainly not the highest.
It may be that President Trump was referring to specific taxes.
Looking at taxes on individuals, Pew Research looked into tax levels in the US last year and considered the tax rates paid by various types of households with different levels of incomes.
It found that US tax bills were below average for developed nations.
For high earners, PriceWaterhouse Coopers did some research in 2014, which looked at the G20 countries, and found that someone earning $400,000 (Â£240,000) in Italy would take home the smallest proportion of their earnings, with the US coming eighth on the list.
For the 2017 tax year, the top rate of income tax was 39.6%, affecting single taxpayers whose income exceeds $418,400, or $470,700 for married taxpayers filing jointly.
If you look at this list of top tax rates from KPMG, Sweden comes out on top at 61.85%.
Turning to corporation tax, the corresponding list from KPMG does put the highest rate for the US at the top (that's 35% federal corporate income tax plus state taxes), with only the United Arab Emirates having a higher rate, which appears to be charged only to foreign oil companies.
The US Congress also did a comparison, which found that the US had the highest statutory corporate tax rate in the G20, although looking at the levels companies were actually paying, the US was third on the list of average corporate tax rates and fourth on the list of effective corporate tax rates.
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At a rally in Ohio on Tuesday, President Trump claimed that the US had the highest taxes in the world.