A 20% charge on cargo: How this blockade is different to the lastpublished at 15:53 BST
Image source, ReutersThis is not the first time Trump has blockaded Iranian ports in the Strait of Hormuz.
In April, US forces announced they would intercept or turn back vessels travelling to or from Iran's coast. The US wanted to restrict Tehran's ability to profit from oil exports in an attempt to put pressure on the country.
The UN's maritime agency, the International Maritime Organisation, says no country has a legal right to block shipping in straits used for international transit.
"We're not going to let Iran make money on selling oil to people that they like and not people that they don't like," Trump said at the time.
Iran called the move "piracy".
The two countries had agreed to lift the blockade and reopen the Strait of Hormuz in the interim deal - or memorandum of understanding - agreed on June 17.
This time round, Trump has also imposed a charge of 20% on all cargo shipped through the vital waterway, but he did not explain how this would work.









