US President Donald Trump is known for his desire for quick deals, writes the BBC.
We had wondered how he might react to the failure to reach an agreement in Islamabad… now we can see his first reaction.
In two lengthy posts on social media, he says he will block some of the ships currently managing to pass through the Strait of Hormuz.
"I have instructed our Navy to search for and stop any ship in international waters that has paid a fee to Iran. No one who pays an illegal fee will have safe passage on the high seas."
Essentially, he also says that “Other countries will be included in this Blockade,” without specifying which ones.
Iran's selective - but effective - blockade of one of the world's most important waterways has generally been bypassed only by ships bound for Iran, countries Tehran considers friendly, or by ships believed to have paid a fee, thought to be around $2 million.
He also suggests that Iran has promised to open the strait.
Based on their public statements, they have consistently said the opposite, seeking formal recognition of what has become perhaps their main strategic point of influence.
If implemented, the president's threat would further limit the amount of oil reaching global markets, with associated economic consequences.
These messages are not a full resumption of hostilities that may have occurred, but they constitute a further escalation.