President Donald Trump declared on Monday that the U.S. will take control of the Strait of Hormuz and said Washington will institute a 20% fee on all cargo passing through the waterway “for any and all costs necessary to do the job of providing safety and security to this very volatile section of the World.”

“The Hormuz Strait is OPEN, and will remain OPEN, with or without Iran,” Trump wrote on Truth Social. “The U.S.A. will be, from this point forward, known as ‘THE GUARDIAN OF THE HORMUZ STRAIT,’ but as such, and as a matter of FAIRNESS, will be reimbursed, at the rate of 20% on all cargo shipped.”

Trump’s comments came after the Islamic Revolutionary Guard Corps announced on Sunday that the strait was considered closed until further notice. 

Trump also said he is reinstating the U.S. blockade on Iran, which had been lifted as part of the memorandum of understanding signed between the two countries last month. The blockade will once again prevent “Iran’s ships or customers from entering or leaving,” he said. “All other countries will have fair and open use of the Strait.”

Earlier on Monday, Trump said during a “Fox & Friends” interview that “we’re going to keep the strait, and we’ll probably run it.” 

Trump has declared the MOU, which said Iran would oversee arrangements for ships transiting the key waterway, as finished.

“We had a deal. It was a done deal, and then they broke it. They always break it,” Trump said of Iran on Monday, declaring his intent to “hit them very hard.” The U.S. struck Iranian targets near the strait on Sunday night after Iran hit a Cyprus-flagged container ship, prompting Iran to fire barrages of drones and missiles at Qatar, Jordan and the United Arab Emirates. 

Iran has attacked several commercial tankers this month for traversing the strait through “unauthorized routes.”

Iran’s Islamic Revolutionary Guards Corps said that normal shipping traffic can only resume if the U.S. ends its military involvement in the strait entirely, according to Iranian state media.