President Donald Trump on Monday said the U.S. will impose fees in the Strait of Hormuz "at the rate of 20% on all cargo shipped," after declaring America the "guardian" of the major oil shipping route.
Trump, in a Truth Social post, also said the U.S. will reimpose its blockade of Iranian ports near the strait, the epicenter of the U.S.' rapidly reescalating war with Tehran. The blockade will resume Tuesday at 4 p.m. ET, U.S. Central Command said.
The U.S. has rejected Iran's own plans to charge tolls to ships passing through the strait, which maritime experts, regulators and even top Trump administration officials have said is illegal under international law. But rather than call for the return of the strait to its prewar status as a toll-free international waterway, Trump's post asserts that commercial vessels attempting the transit must now pay protection money to the U.S.
Oil prices jumped, and stock indexes fell, following Trump's announcement.
The strait, which saw 20% of the world's oil trade before being choked off at the start of the war in late February, "is OPEN, and will remain OPEN, with or without Iran," Trump wrote in the post.
All countries other than Iran will "have fair and open use of the Strait," Trump wrote. The assertion came amid new exchanges of fire between the U.S. and Iran that have put the prospect of a peace deal further out of reach, while once again slowing tanker traffic in the strait to a trickle.
"The U.S.A. will be, from this point forward, known as 'THE GUARDIAN OF THE HORMUZ STRAIT,'" he claimed. "But as such, and as a matter of FAIRNESS, will be reimbursed, at the rate of 20% on all cargo shipped, for any and all costs necessary to do the job of providing safety and security to this very volatile section of the World."
"The process and formation will begin immediately," he added.
Much about the proposed reimbursement policy was unclear. The White House did not immediately respond to CNBC's questions about Trump's post.
Iranian foreign minister Abbas Araghchi said in an X post Monday afternoon that Iran, not the U.S., controls the strait and deserves to "be compensated for this service."
"20% is of course too much. We will be fair," Araghchi wrote.
The United Nations' International Maritime Organization, which regulates maritime transport, said after Trump's post that it "stands firmly against charging fees for passage through straits used for international navigation."
"There is no legal basis through which to introduce mandatory tolls simply to transit through a strait," the organization said in a statement to CNBC.
That stance echoes the one offered by U.S. Secretary of State Marco Rubio, who said last month, "No country is allowed to charge tolls or fees on an international waterway. That's existing international law."
It's not unprecedented for the U.S. to offer protection services to vessels in the Persian Gulf — it did so for Kuwaiti ships under fire from Iran in the 1980s, for instance.
But slapping a 20% charge on ships is "quite an extortionate level," especially since "it's unclear that the U.S. can deliver safe passage in the first place," said David Goldwyn, president of Goldwyn Global Strategies and a former U.S. State Department special envoy during the Obama administration.
"If the U.S. was able to safely escort ships and guarantee no threat from Iran, we would have seen that happen in the past few weeks," Goldwyn told CNBC in a phone interview. "So I think this is really just bluster."
Trump telegraphed the policy announcement in a Fox News interview earlier Monday morning, when he said the U.S. is "going to get paid for guarding" the strait.
"We're going to keep the strait, and we'll probably run it," Trump said.
"We'll become the guardian of the strait — maybe we'll call it the guardian angel of the strait," Trump told Fox. "And we should be reimbursed for that."
"We can't be expected to do that for nothing, unlike we had for many years," he added. "We guarded it for nothing, and now we're going to guard it, we're going to get paid for guarding it. A lot of money."
Since the conflict began, Iran has signaled plans to charge tolls or other fees for ships transiting the waterway — a scenario the U.S. has rejected.
The temporary ceasefire deal the U.S. and Iran signed in mid-June explicitly prohibited Tehran from imposing any charges on commercial ships passing through the strait.
But that deal has been so undermined by repeated attacks in the region that Trump last week declared the ceasefire was "over."
Trump has previously floated the possibility that the U.S. could charge money to transiting commercial vessels in the strait.
Days after the 60-day ceasefire deal was signed, Trump wrote on Truth Social that there will be no tolls "unless they are imposed by and for the United States of America, should the deal not be completed, for services rendered as the Guardian Angel to the countries of the Middle East for purposes of both past, present, and future reimbursement of costs."
His latest comments show him doubling down on that possibility in the wake of the ceasefire's erosion.
— CNBC's Spencer Kimball contributed to this report.
Facts Only
* President Trump announced a 20% fee on all cargo shipped in the Strait of Hormuz.
* Trump claimed the U.S. is the "guardian" of the major oil shipping route.
* The U.S. will reimpose its blockade of Iranian ports near the strait, resuming Tuesday at 4 p.m. ET, according to U.S. Central Command.
* The U.S. rejected Iran's plans to charge tolls for ships passing through the strait.
* Trump asserted the Strait remains open regardless of Iran.
* The U.S. claimed it would be reimbursed at a rate of 20% on all cargo for security and safety costs.
* Iranian foreign minister Abbas Araghchi stated that Iran, not the U.S., controls the strait and deserves compensation.
* The United Nations' International Maritime Organization stated there is no legal basis for introducing mandatory tolls through straits used for international navigation.
* A previous deal explicitly prohibited Iran from imposing charges on commercial ships passing through the strait.
Executive Summary
President Trump announced that the United States would impose a 20% fee on all cargo shipped through the Strait of Hormuz, claiming the U.S. is the "guardian" of this major oil shipping route and would be reimbursed for security costs. The announcement was coupled with a statement that the U.S. would reimpose its blockade on Iranian ports near the strait, which U.S. Central Command said would resume Tuesday at 4 p.m. ET. Trump asserted that the Strait remains open, regardless of Iran's status, and stated that all countries except Iran will have "fair and open use" of the waterway.
The proposal directly rejected Iran's own plans to charge tolls for passage, which maritime experts and regulators deem illegal under international law. This action follows recent escalations between the U.S. and Iran, which have reduced tanker traffic in the strait. While some observers view this as an assertion of authority, others question the legality and practical execution of imposing such fees on an international waterway. Iranian officials countered by asserting that Iran, not the U.S., controls the strait and should be compensated for services provided. International maritime organizations expressed opposition to introducing mandatory tolls through straits used for international navigation.
Full Take
The narrative hinges on a fundamental tension between asserted sovereign authority and established international maritime law. The core mechanism being proposed—imposing arbitrary fees as protection money—collides directly with established norms regarding international waterways, as evidenced by the opposition from maritime organizations and U.S. State Department officials who cite existing international law against tolls. This dynamic suggests that the action is less about operational necessity and more about establishing a new, unilateral regulatory framework rooted in geopolitical power rather than legal precedent.
The claim of being the "guardian" and the subsequent demand for reimbursement operate as rhetorical tools designed to frame a coercive act as a service rendered. The stark contrast between Trump’s assertion of control over the Strait—stating it remains open with or without Iran—and the counter-claims from Tehran regarding ownership highlights a dispute over whose jurisdiction and legal authority should govern this critical choke point. Furthermore, the skepticism raised by experts regarding the feasibility of guaranteeing safe passage before levying substantial charges suggests that the announcement functions primarily as political bluster intended to signal intent rather than a fully realized policy based on agreed-upon legal or logistical reality. The potential for this framing to incite immediate reaction is significant because it forces observers to weigh geopolitical outcomes against the established principles of free navigation and international adjudication.
Bridge Questions: If the U.S. establishes a precedent for non-consensual tolling in critical international transit zones, what are the predictable long-term consequences for global maritime governance? How does the framing of security as a direct monetary transaction shift the accountability structure away from established legal bodies toward executive decree? What alternative frameworks exist for ensuring security and access to these straits that do not rely on unilateral assertion of dominion?