Brent futures briefly climbed above $100 a barrel in London, after falling earlier when Iran said it received “some sign” that the US was willing to end its blockade, opening the path for talks.

Crude has been whipsawed by mixed signals from both sides, while shipping through Hormuz, a vital artery that normally carries about one‑fifth of global crude flows, remains at a near-halt. Volatility has soared to its highest since 2020, when the Covid pandemic sapped demand.

US President Donald Trump indefinitely extended a ceasefire with Iran just before its expiration, while maintaining a naval blockade of the strait after planned talks between the two sides fell apart. He said the US would hold off on fresh attacks but keep blocking ships linked to the Islamic Republic until “discussions are concluded, one way or the other.”

Trump later said in a post on Truth Social that if the US lifted its blockade to open the Strait of Hormuz, “there can never be a Deal with Iran, unless we blow up the rest of their Country, their leaders included!”

The UK Navy said two ships were fired at near the Strait of Hormuz, the latest incidents following shootings over the weekend that ratcheted tensions higher in the vital waterway and kept maritime traffic at a near standstill.

Iran won’t reopen the strait as long as the US Navy continues to intercept ships and will, if necessary, break the blockade by force, Tasnim reported earlier, citing sources. The US on Tuesday said it stopped and boarded a sanctioned oil tanker, after seizing a cargo ship over the weekend, and has turned around a total of 28 vessels.

“As long as flows through the Strait remain restricted, the market keeps tightening up, keeping prices supported,” said Giovanni Staunovo, an analyst at UBS AG in Zurich.

At least two fully laden Iranian tankers have sailed out of the Persian Gulf and past a US blockade this week, part of a flotilla that has made its way around the warships and ferried roughly 9 million barrels of oil to the market.