President Donald Trump's proposal to impose a 20% toll on commercial cargo transiting the Strait of Hormuz could generate as much as $194 billion a year for the U.S. if fully implemented, according to a New York Post analysis based on prewar shipping volumes.

The Post, citing supply chain data from Exiger CEO Brandon Daniels, reported that between $880 billion and $970 billion in international commerce moved through the strategic waterway each year before the Iran war, meaning a 20% fee could produce between $176 billion and $194 billion in annual revenue.

Trump announced the proposal Monday as he declared America would become the "Guardian of the Hormuz Strait" while reinstating the U.S. blockade of Iranian ports.

"The U.S.A. will be ... known as 'THE GUARDIAN OF THE HORMUZ STRAIT,'" Trump wrote, adding that the U.S. should be "reimbursed, at the rate of 20% on all cargo shipped," for providing security in the vital shipping lane.

According to the Post, the projected revenue would be enough to cover the salaries of roughly 1 million federal civilian employees, although the administration has not explained how the toll would be collected or enforced.

Daniels told the newspaper that significant legal and logistical hurdles remain, including whether the U.S. could lawfully impose such a fee under international maritime law and what agency would collect it.

The proposal has already drawn international criticism.

A panel of independent experts appointed by the United Nations Human Rights Council argued that charging commercial vessels for passage through an international strait would violate international law and warned the plan could undermine the long-standing principle of freedom of navigation.

The proposal also represents a reversal from Washington's earlier position on transit fees in the Strait of Hormuz.

When Iran previously floated the idea of imposing its own tolls on ships using the waterway, the U.S. rejected the proposal, arguing the strait is an international passage where vessels have a right of unimpeded transit under international law.

Iran also rejected Trump's proposal, with Foreign Minister Abbas Araghchi arguing Tehran — not Washington — has long served as the strait's guardian while deriding the proposed 20% charge as excessive.

The Strait of Hormuz remains one of the world's most important maritime chokepoints, carrying hundreds of billions of dollars' worth of crude oil, liquefied natural gas, and other commodities each year, and any disruption to traffic through the narrow waterway can ripple through global energy markets.