Donald Trump says the US will become the "guardian" of the Strait of Hormuz, reinstating a naval blockade on Iranian ports beginning Tuesday at 16:00 ET. In a Truth Social post, he announced a 20% charge on all cargo shipped through the vital waterway to cover the cost of "safety and security." The UN's International Maritime Organization said it "stands firmly against charging fees for passage through straits used for international navigation," stating there is "no legal basis" for mandatory tolls. Iran earlier warned the US not to "interfere in the management" of the strait. Meanwhile, US Central Command said it hit a submarine and Iranian ship maintenance facility overnight in response to Iran targeting commercial vessels. Oil prices rose as shipping traffic remains restricted, with the Joint Maritime Information Centre advising mariners to expect a "sustained naval presence" and potential enforced protection measures.