Two rival blockades of the strategic Strait of Hormuz are now blocking progress in the talks.

Neither the US nor Iran shows any sign of backing down.

The US believes the grievous economic cost of this closure will push Tehran back to the negotiating table to accept its deal. Iran is certainly paying a steep price.

We see it in this city. People tell us about job losses and price rises - they voice their worries about what’s to come.

But Iran’s leaders won’t capitulate. It’s not in the DNA of this system.

They believe they can absorb this pain, that the US will blink first. Intensive efforts are under way, including by the main mediator, Pakistan, to break this impasse.

Yesterday, Iran’s lead negotiator, Mohammad Bagher Ghalibaf, posted on social media that the US blockade of its ports, as well as President Donald Trump’s repeated threats to bomb Iran, violated the ceasefire - he called them the main obstacles to “genuine negotiations”.

Iran also has its commitments to keep under the terms of the fragile ceasefire, to “completely open” this maritime corridor. But it’s clear it will only ever be ready to do it, on its terms.

-BBC