US-Iran ceasefire on brink of collapse as talks stall and Strait of Hormuz crisis deepens

Published on 21/04/2026 - 10:20 GMT+2

The US and Iran both warned they were ready to resume the war as the ongoing ceasefire nears its expiration, as the fate of the second round of high-stakes peace talks between Washington and Tehran remains unclear.

The White House said Vice President JD Vance was ready to fly back to Islamabad to lead the US delegation, which would also include US President Donald Trump’s special envoy Steve Witkoff and the president’s son-in-law Jared Kushner.

They were initially planned to take place in the Pakistani capital on Monday, but were disrupted after Iran announced its withdrawal from the talks aimed at ending the war, which has engulfed the Middle East and shaken global markets.

Tehran's withdrawal was partly sparked by the US seizure of an Iranian-flagged cargo vessel en route to a port on Sunday. The US Navy said the ship had not complied with its warnings and was attempting to evade its blockade of Iranian ports.

The blockade came into effect last week in response to Iran’s closing of the Strait of Hormuz since the beginning of the war on 28 February, which sent oil prices spiralling worldwide.

Iran said the naval blockade of its ports is a violation of the ceasefire agreement, which the US refutes. Trump insisted that the US Navy will continue to enforce it until Iran reopens the strategic waterway it controls to maritime traffic, without conditions.

“The blockade, which we will not take off until there is a 'deal,' is absolutely destroying Iran. They are losing $500 million ... a day, an unsustainable number, even in the short run,” wrote Trump in a post on Truth Social.

Tehran also said it refuses to engage in any diplomatic efforts under the threat of attack, after Trump, in various posts on social media over the last few days, threatened to intensify the fighting and “blow up” the entire country if it fails to enter into a deal with Washington.

“Trump, by imposing a siege and violating the ceasefire, seeks to turn this negotiating table — in his own imagination — into a table of surrender or to justify renewed warmongering,” wrote Iran’s parliament speaker Mohammad Bagher Ghalibaf on X on Monday.

“We do not accept negotiations under the shadow of threats, and in the past two weeks, we have prepared to reveal new cards on the battlefield,” he added.

Iran's Revolutionary Guard Corps (IRGC) — an elite unit with its own navy answering directly to the ayatollah — warned of targeting any vessel attempting to pass through the Strait of Hormuz without permission.

The waterways facilitate the passage of roughly one-fifth of the world’s oil exports, gas and other crucial items like fertilisers.

Brent crude, the international standard, traded at just over $95 a barrel on Tuesday, a steep drop-off from the close to $120 figure it reached prior to the ceasefire, but still a roughly 40% hike compared to prices in early February.